Top IV Drugs in Acute Care Medicine

D. John Doyle MD PhD

Revised April 2004

Adenosine

Brand name Adenocard. A great drug with a minimal half-life (rapid enzymatic clearance) used for quickly terminating paroxysmal supraventricular arrhythmias to sinus rhythm or to distinguish between paroxysmal supraventricular tachycardia and other tachycardias. Not useful to convert atrial flutter, atrial fibrillation or ventricular arrhythmias (for ventricular arryhtmias start with lidocaine). Thus it is important to know which rhythm you are dealing with, and to use an ECG monitor. Adult Dose: Give 6 mg IV by fast push, with 10 ml of saline instantly followed as a "chaser" to flush the drug through. Expect to see a several second period of asystole prior to the birth of the new rhythm. Initiate CPR/ACLS if the asystole lasts too long. This is a drug to carefully review  before using.

Aminophylline

This fading star is still occasionally used as an infusion for acute asthma treatment, but its popularity has waned following the introduction of more effective (and far less toxic) beta agonist therapy such as inhaled albuterol (trade name Ventolin; generic name albuterol). Another reason aminophylline is only rarely used now is its tendency to cause cardiac arrythmias and seizures, as well as its many drug interactions.

So why is it on this list? Because it might be on the exams. Just thought you should know.

Ancef

Generic first generation cephalorosporin antibiotic often used by surgeons e.g. 1000 mg IV q8H. Generic name cefazolin Cross-reactivity to Ancef is a potential problem in patients allergic to penicillin; thus Ancef is a not first-line agent in these individuals (but vancomycin (or nothing) might be).

Ampicillin

This antibiotic is frequently used as part of endocarditis prophylaxis protocols. It is also commonly used in treating respiratory and ear infections in outpatients.

Atropine

Used to increase heart rate via its vagolytic effect (sometimes also used as a drying agent - i.e., as an antisialogue). Patients that are severely bradycardic (low heart rate) need empirical treatment as well an investigation regarding causation (heart block, hypoxemia, beta blocker overdose, etc.). The intervention threshold for bradycardia (deciding at what level to treat) is a matter of clinical judgement, but I think that no-one should be allowed to drop under 35 beats / min for a significant period of time even if the patient is demonstrating no other clinical problems such as hypotension.

Atropine should be given with special care in the elderly and in patients with coronary artery disease because excessive increases in heart rate may not be well-tolerated (risk of myocardial ischemia). Patients requiring atropine to control heart rate should be on a electrocardioscope (ECG monitor). Renal clearance.

Adult dosing suggestions:

0.3 mg IV to treat light bradycardia (45-50 bpm) or in individuals with possible coronary artery disease (although glycopyrolate 0.2 mg IV may be better).

0.6 mg IV for more agressive treatment

1-2 mg IV may be called for in the Acls protocol for cardiac arrest

0.6 mg IM is sometimes given in individuals suspected to have dangerously high vagal tone levels (eg, those subject to vasovagal attacks, or those with previous bradycardic experiences), but use of glycopyrolate 0.4 mg IM 1 hour preop would be a more popular order.

Patients with bradycardia unresponsive to atropine may need CPR, isoproterenol by infusion, or cardiac pacing. Review your Acls algorithms (You took the Acls course, didn't you?)

Calcium Chloride

This drug is used to treat hypocalcemia such as might occur following a massive blood transfusion (the citrate anticoagulant added binds calcium). It is often used in the ICU or to combat hypotension when coming off cardiopulmonary bypass. Calcium administration also protects the myocardium from deadly rhythm disturbances which accompany hyperkalemia. I usually give calcium chloride in increments of 100 to 300 mg IV push. Calcium gluconate can also be used, but has only one third the amount of elemental calcium per gram.

Cimetidine

Hailed as the prototype H2 blocker to reduce stomach acidity, a series of drug interactions and other flaws has led to a drop in its popularity. Newer agents such as ranitidine (Zantac) and Pepsid are now fighting valiently for the market share once owned by cimetidine. The best-known brand name for cimetidine is Tagamet.

Cyclokapron

Generic name traxemic acid. An antifibrinolytic agent that counteracts the stuff that breaks fibin down into degradation products(fibrinolysins). Give 50 mg/kg IV by minibag before heart surgery (more for redo cases) or a smaller dose prior to liver transplantation (15 mg/kg). Wise use of this product will reduce the need for blood transfusions. Two concerns exist for this drug: (1) cost, (2) theoretical risk of thromboses.

Diltiazem

This calcium channel blocker has antianginal and antiarrhtyhmia properties, but I've never used it. It is sometimes preferred over beta blockers to reduce the heart rate in individuals with Copd.

Dobutamine

This drug is often used in clinical situations where dopamine may have too much alpha effect, causing increases in afterload. This drug is often used as a first line inotrope in coronary care units to increase cardiac output.

Droperidol

This drug is often used as a second or third line drug to treat nausea. Brand name Inapsin. Nausea Treatment: First line - Gravol, Second Line - Stematil, Third line - droperidol or ondansetrol.

Edrophonium

This drug causes acetylcholine to buildup at the neuromuscular junction, the site where muscle relaxants work. Since muscle relaxants competitively displace acetylcholine molecules from receptors, anticholinesterases like edrophonium or neostigmine can be used to reverse neuromuscular blockade. When used in this setting, however, atropine or glycopyrolate are always given to prevent Dangerous Bradyarrhythmias since use of edrophonium or neostigmine on its own can bring heart rates into the 20s or worse. Brandname Tensilon.

Edrophonium is also used (with EKG monitoring) in small doses 5-10 mg to help diagnose myasthenia gravis ("Tensilon test") or to diagnose / treat some supraventricular arrhythmias. The drug is used most frequently (99%) by anesthesiologists.

Digoxin

Given orally, this drug has mild inotropic properties and is often used in treating patients with poor ventricular performance (such a heart failure patients). The drug is well known to have a toxic side to it ("dig. toxicity"), which is why "dig. levels" can sometimes be helpful to warn against potentially toxic amonts of digoxin.

More commonly we see patients on digoxin because of atrial fibrillation (no P waves on ECG, irregularly irregular pulse), since digoxin often helps reduce the heart rate when the ventricular response to atrial fibrillation is excessive (as in 130 beats per minute). To treat this give a loading dose of digoxin of 8 - 12 mcg/kg IV slowly, followed by a daily maintenance dose of one-third that size. Other options to consider are cardioversion back to sinus rhythm and the use of a beta blocker such as esmolol or metoprolol. More fragile patients may not tolerate atrial fibrillation and the decreased LV filling that comes with it, and may require treatment using means faster than digoxin. Patients with new onset atrial fibrillation occuring under general anaesthesia may especially benefit from prompt cardioversion (see Acls guidelines); patients experiencing awake cardioversion describe it as "quite a kick to the chest". Renal and hepatic clearance. Toxicity increased with hypokalemia.

Diazepam

Soother to millions of anxiety-prone housewives under the trade name Valium, diazepam is is both effective and cost-effective as an anxiolytic. (Obviously the drug is now available as a generic).

It plays a special role in sedation for procedures done the operating room or ICU by dimming the flame of consciousness. The state produced often has a euphoric edge, but in larger doses can result in respiratory depression and apnea that has occasionally cost some lives.

I give IV diazepam incrementally, 2 mg at a time, although some others give 5 mg or more at a time. The drug may sting when it enters the vein, although this is less likely if given slowly into a free-running IV; the problem vanishes if given as a lipid soluble emulsion (Diazemuls).

IV diazepam may be given IV push in 5-10 mg doses for the empirical treatment of grand-mal seizures prior to starting the patient on a conventional anticonvulsant such as phenytoin (Dilantin). Special concerns about airway management exist in this setting.

Wherever possible, watch for respiratory depression using pulse oximetry and nasal capnography, in addition to visual inspection of breathing.

Diazepam and all the other benzodiazepines may be reversed by displacing the drug from body "benzo" receptors by giving 100 mcg (microgram) increments of flumazenil.

Diazepam undergoes hepatic and renal clearance.

Dopamine

What Intensive Care Unit (ICU) or cardiac operating room (OR) could function without dopamine, that honorable old, inexpensive, reliable, first-choice inotrope? Despite its age, its a mighty potent heart tonic, and can only be given by dilute infusion (usually 200 mg mixed in 250 ml of 5% dextrose at 2-20 mcg/kg/hr) through a central line. When given at "renal dose" (2-4 mcg/kg/hr) a diuresis often results in a patient previously refractory to diuretics. Despite enthusiastic adoption by some intensivist types, controversy still exists about its true role in managing or preventing oliguria in patients in the OR or ICU.

Less controversial is its role as an inotrope. It is usually the first choice inotrope in patients who are are not tachycardic and who are not hypovolemic. Inotropic doses of dopamine are in to 5-20 mcg/kg/hr range, and should result in desirable increases in blood pressure and cardiac output. (Under 10 mcg/kg/hr the effect is mostly beta; over this amount, alpha effects predominate - roughly speaking).

Regretably, however, even moderate use of dopamine may sometimes result in tachycardia (potentially hazardous in patients with coronary artery disease).

Other inotopes and vasporessors you might find in your hospital: Dobutamine, Epinephrine, Norepinephrine, Phenylephrine and Ephedrine.

Epinephrine (Adrenalin)

Natures own inotrope is cheap, potent and dangerous, like Kentucky moonshine. And epinephrine is much more than just an inotrope - it's chronotropic properties are sure to speed up just about any heart.

Also, adding epinephrine to local anesthetics (1:200,000 dilution) makes the anesthesia last longer (vasoconstriction effect). But don't use epinephrine for anaesthesia to fingers, toes or penis (things might become gangrenous and fall off).

But the real place of epinephrine in emergency medicine is two fold:

(1) Managing anaphylaxis and

(2) Running a code (executing the Acls cardiac arrest algorithm)

For true anaphylaxis give epinephrine in doses of 2 to 4 mcg/kg repeated every five minutes as needed, by the IV route if possible (IM or SC routes OK but less effective).

Epinephrine plays prominently in "running a code", acting as an inotrope, a chronotrope, and tightening up vascular tone to allow for a good diastolic pressure. In a full cardiac arrest it is given 1 mg (1000 mcg) at a time. (If an IV has not yet been established, the drug may be given via the ETT). For details take the Acls course.

Epinephrine is also used in smaller amounts for blood pressure support as 5-10 mcg bolus doses or as an infusion (0.1 to 0.5 mcg/kg/min).

Finally, it should be noted that racemic epinephrine is often administered by inhalation using a nebulizer to reduce airway edema, to treat some forms of stridor, and as a bronchodilator

Fentanyl

This shortish acting narcotic analgesic remains a staple of clinical anesthesia, despite the agressive marketing of newer agents such as sufentanil or alfentanil with apparently better technical specs. Almost every general anesthesia adult patient gets a customary 100 mcg or more of fentanyl to "smoothen" the induction. In cardiac surgery enormous fentany doses (50-100 mcg/kg) are used as an offer to the anesthesia gods, praying as it were for a smooth hemodynamic course. More practical doses of 10-15 mcg/kg of fentanyl are used in centers advocating "early extubation" following cardiac surgery.

Fentanyl is often given in small doses 50-100 mcg in Emergency Department to provide short duration analgesia.

Flumazenil

The most important use of this drug is to reverse the effect of benzodiazapines such as diazepam (Valium) or midazolam (Versed). Give it 100 micrograms at a time until the patient is more alert. Drowsiness from alcohol, barbiturates, and narcotic analgesics will not be reversed even slightly with flumazenil, so before you keep giving multiple repeats of flumazenil, keep in mind other causes of drowsiness (increased intracranial pressure from trauma, tumor or bleed; metabolic disturbances such as hypoglycemia, hypercarbia, or hypoxemia).

The drug is often used to increase the alertness of patients in the recovery room or in the endoscopy suite (where midazolam use is popular). It is occasionally used empirically in the generic treatment of unconscious victims of unknown etiology, where it may be coadministered with IV glucose (in case of hypoglycemia), IV naloxone (in case of opiate overdose) and IV thiamine (in case of thiamine deficiency). Special caution applies when flumazenil is given to patients chronically on benzos - you may precipitate withdrawl symptoms, even seizures.

Furosemide

Furosemide, perhaps better known by the trade name Lasix, is an effective diuretic when a prompt diuresis is needed to manage congestive heart failure, pulmonary edema and the like. Many patients are chronically on furosemide as a guard against heart failure; such patients must be followed for hypokalemia, as diuretics sometimes severely deplete body potassium.

In normal individuals the dose given is 10-20 mg IV push and this results in a quick, sustained diuresis. Double the dose (20 mg IV push, then 40 mg , then 80) every 20 - 30 minutes may be needed if no response is seen. However, before getting carried away with escalating the dose, be sure that the foley cathetery is in place and is not kinked or blocked. And be sure that the oliguria you are so aggressively treating is not, in fact, due to hypovolemia, since oliguria is a normal response to this state, and giving furosemide in this setting will further worsen the hypovolemia.

Doses in excess of 500 mg IV are not uncommon in patients in renal failure. Patients who respond poorly to furosemide are often tried on doses of ethacrynic acid or zaroxyln.

Patients on potent diuretics such as furosemide must have their electrolytes followed, especially for potassium disturbances, since diuretics flush electrolytes (esp K) from the body.

Gentamycin

Tobramycin and gentamycin are well-known aminoglycoside antibiotics particularly active against gram negative organisms. Aminoglycosides are sometimes ototoxic, causing damage to the eighth cranial nerve. (ICU survivors of sepsis sometimes develop deafness).

Whereas opinion once held that aminoglycosides should be given with particular attention to keeping drug levels within a particular therapeutic window ("not too low; not too high"), consensus is now drifting towards once-a-day dosing with doses that would at once have been considered excessive.

Gentamycin loading dose is usually 1.5 mg / kg. When renal function is normal the maintenance dose is 1 mg /kg q8H.

Glycopyrrolate

This drying agent is often given IM (e.g. 0.4 mg IM 1 hr preop) to keep the airway dry for airway procedures (e.g., fiberoptic intubation). It can also be used IM or IV to reduce the likelihood of "vasovagal" bradycardias that are common in individuals with high vagal tone. It is also often co-administered with neostigmine to prevent bradycardia following the reversal of muscle relaxants. Example: neostigmine 2.5 mg with glycopyrolate 0.4 mg

Heparin

Another Toronto discovery like insulin, heparin made open heart surgery first possible in the sixties by preventing blood from clotting on contact with an artifical surface. Full heparinization is needed for successful cardiopulmonary bypass (CPB) and the anticoagulant effect is monitored by following the ACT (activated coagulation time). A normal ACT is under 200 sec(or there abouts) but should be in excess 400 sec for CPB to proceed safely. This usually requires heparin in doses of 300 units per kilogram or more.

Following CPB, the heparin is reversed with protamine, a wonderful but occasionally mischievous drug derived from salmon. (Protamine may induce anaphylaxis in individuals allergic to salmon.)

Heparin is often given in smaller amounts for vascular surgery (eg 5000 units IV push) or in reducing the likelihood of acute coronary insufficiency leading to myocardial infarction.

Hydralazine

Direct-acting arterial vasodilator that takes 10-20 min to work. Refex tachycardia can be prevented with coadministration of a beta blocker such as metoprolol. I usually use hydralazine with a transduced arterial line in place, since I'm an anesthesiologist. I usually give 2-5 mg IV push at a time, waiting 15-30 min or more before giving more. Trade name Apresoline.

Insulin

This fine Canadian discovery can still be tricky to use despite 70 years of refinement. Ambulatory diabetics will get blood glucose data one or more times a day using a glucometer and use this, along with information about meal size and the like, to decide on an insulin dosing strategy. Some diabetics, in an attempt to minimize long-term complications of diabetes, try for aggressive control of blood glucose levels with a glucose check and new insulin dose following each meal (3 to 4 times per day). This can get complicated, which is why new diabetics are (or should be) sent to "diabetes school" to learn about the carbohydrate exchange system, forms of insulin, and similar goodies. (Special emphasis should also be place on training the patient in sound glucometer use).

You are likely to need insulin in a hospital setting to treat any of the following:

1. hyperglycemia

2. hyperkalemia

Treatment of Hyperglycemia Using Insulin

The use of insulin to treat hyperglycemia is by far its more important application, unless you work on a renal service. Patients who are in an acute care setting are often too ill to eat, but may present with hyperglycemia in response to stress or because of diabetes. Such a situation can progress into frank diabetic coma or a related condition known as Hyperosmolar Nonketotic Coma, both high-risk clinical situations.

I often place hyperglycemic patients on an insulin infusion postoperatively if they came to the OR with the infusion preop or if I have a special concern about the patient. One approach is to add 25 units of regular insulin to a 250 ml bag of 5% dextrose (that makes a ratio such that 10 ml solution = 1 unit of regular insulin. ). The infusion rate you pick to start with will depend on a number of factors: how aggressively you wish to lower the sugar, how dangerous a hypoglycemic episode will be, how fast the sugar is changing, and in what direction, etc. Coming up with an actual number for a particular dose in a particuler clinical setting is part of the art of clinical medicine, and it comes best with practice.

The above, not withstanding, I can still offer some reasonable starting guidelines:

For mild hyperglycemia, do not give insulin and get Q6H sugars by glucometer

For moderate hyperglycemia start at 1-2 units per hour of regular insulin (run infusion at 10 - 20 ml/hour) and get Q2H sugars to guide further therapy

For severe hyperglycemia start at 2-4 units per hour and get Q1H sugars

Notice that I didn't specifically define the ranges for mild, moderate and severe hypoglycemia. If you needed a scale to implement these rules in algorithm form, one of many possibilities would be: mild = under 150 mg/dl; moderate = 151 to 250 mg/dl; severe = above 250 mg/dl). (You can even incorporate fuzzy logic principles into this stuff).

In addition, bolus doses of insulin (5-15 units) will often be required to speed up the normalization of sugar levels. Large choices of insulin bolus dose may lead to hypoglycemia and patient injury, so be sure to get sound advice before giving bolus doses of insulin.

Like the game of blackjack, you can go bust using insulin therapy. If you are too aggressive with insulin (or fail to monitor blood glucose properly) you may produce iatrogenic hypoglycemia. This tends to fry the patient's brain (ie, result in irreversibe neurological injury). Hypoglycemia may be suspected if a patient loses alertness following an insulin dose. If confirmed by a quick emergency glucometer reading, initiate treatment using a bolus of intravenous glucose (25-50 gm).

Treatment of Hyperkalemia Using Insulin

Insulin is also used in the treatment of hyperkalemia, since insulin causes both glucose and potassium to enter into cells. In the hyperkalemic patient with concurrent hyperglycemia (common in the cardiac OR) insulin administration will lower both glucose and potassium levels and is often given as 5-15 unit boluses, but is also sometimes given by infusion.

In patients who are hyperkalemic but not hyperglycemic, insulin therapy will help correct the potassium but may kill the patient unless you supply IV sugar (eg 50 gm dextrose) to the patient concurrently. Read your textbook for details.

One can also lower potassium ion concentration by taking measures to lower the hydrogen ion concentration, ie increase blood pH. Both hyperventilation and bicarbonate administration will do this, but the former method requires that the patient be intubated.

More definitive removal of potassium can be achieved using hemodialysis (ask the renal service about appropriateness) and potassium exchange resins (eg potassium kayexolate). Diuretics such as furosemide can also be helpful.

IV calcium chloride may also be given to counteract the deleterious effect of hyperkalemia on cardiac conduction and electrophysiology (pacing and rhythm).

Isoptin

see verapamil

Ketamine

This drug causes a strange "dissociative" state approximating general anesthesia when given in sufficient amounts (eg 1-2 mg/kg IV push. In much smaller amounts it may be useful as a sedative with analgesic properties. It is popular as an inexpensive but safe anesthetic agent in the third world, often given IM where venous access is impossible. It is commonly used in initiating emergency anesthesia for hypovolemic patients (eg, ruptured ectopic pregnancy or ruptured AAA), since the drug preserves cardiac performance better than thiopental or propofol. Ketamine is also used for anesthesia in asthmatic patients and is occasionally used recreationally.

Neostigmine

This drug causes acetylcholine to buildup at the neuromuscular junction, the site where muscle relaxants work. Since muscle relaxants competitively displace acetylcholine molecules from receptors, anticholinesterases like neostigmine or edrophonium can be used to reverse neuromuscular blockade. When used in this setting, however, atropine or glycopyrolate are always given to prevent Dangerous Bradyarrhythmias since use of neostigmine or edrophonium on its own can bring heart rates down to the 20s or worse.

Labetalol

A gentle beta-blocker with a nice alpha-blocking side to it. I rarely use it, prefering metoprolol for no special reason other than familiarity and availability. Also, it comes in 20 ml ampules, when only 5 to 10 ml are usually needed (waste problem if not needed for a prolonged period).

Lasix

Brand name of furosemide.

Lidocaine

Useful both as a local anesthetic and as a treatment for ventricular arrhythmia, lidocaine is a true clinical workhorse, available straight (no preservatives), with preservatives (multidose vials) and with added epinephrine (to extend local anesthesia duration).

Lidocaine may be given for local anesthesia in a dose not exceeding 5 mg/kg (7 mg/kg when epinephrine is added). For a 70 kg man one could thus give give up to 350 mg of plain lidocaine before being seriously worried about the possibility of a grand-mal convulstion or cardiovascular collapse. 350 mg of plain lidocaine is 35 ml of 1% lidocaine or 17.5 ml of 2% lidocaine. Remember that a 1% solution has a concentration of 10 mg/ml.

For treatment of ventricular ectopy (premature ventricular beats, runs or salvos of ventricular tachycardia, etc.) give 1 to 1.5 mg/kg by IV push, followed, if needed, by a second half-strength dose a minute or two later. Some cases will benefit from an infusion of lidocaine at a rate between 1 and 4 mg/min (start at 2 mg/min).

Brand name Xylocaine. Hepatic clearance.

Magnesium

Intravenous magnesium has a long history of use in treating preeclampsia (an obstetrical condition featuring hypertension, hyperreflexia and proteinuria). It is given as an infusion for this purpose. Loading dose: 1- 4 gm IV over several minutes. Infusion: 4 gm in 250 ml NS to run at a rate guided by clinical findings and serum magnesium levels.

In patients exhibiting ventricular ectopy due to suspected hypomagnesemia (following cardiac surgery, for instance) I some times administer 2 grams of magnesium over several minutes.

Overdoses of magnesium may lead to muscular weakness and ECG changes and may require treatment by giving IV calcium. Toxicity is seen when serum magnesium exceeds 7 - 10 mEq/L.

Metoprolol

Cardioselective beta blocker. Brand name Lopressor.

Every hypertensive tachycardic heart needs a beta blocker to bring it back into range. Metoprolol is a popular drug to use for this purpose. I give it 1 mg IV push at time (adults, obviously), but some people give it much more aggressively, even 5 mg at a time (but then, I've been burned once).

Remember the trouble you can get into with beta blockers. Even with allegedly cardioselective drugs like metoprolol, broncospasm could result in asthmatic patients, and the myocardial depressant effect of beta blockers is especially hazardous in patients with poor left ventricular function.

Renal clearance.

Other beta blockers you may meet:

Propranalol, the original, nonselective, beta blocker

Esmolol, the expensive, quick-acting beta blocker for people seeking close control during difficult hemodynamic storms

Midazolam

Midazolam is a short-acting benzodiazepine sedative popular in the OR and ICU because of its short duration and its specific reversability with flumazenil. It goes by the trade name Versed. I t's easy to get into trouble with midazolam, especially if you give it freely and then fail to monitor the patient (as has sometimes occured when endoscopists become enamoured with a rectal polyp at the end of a colonoscope and ignore the the patient's breathing).

Midazolam is given in increments of 0.5 to 1.0 mg IV push until an appropriate degree of sedation is achieved. An example of its humane use is to sedate patients in the ICU or for a surgical procedure done under local anesthesia. An example of it's inappropriate use is as first line therapy for acute pain (where an analgesic would be appropriate).

Renal clearance.

Morphine

The Queen of Analgesics, morphine is cheap and reliably effective, but carries some deadly stingers by way of side effects (respiratory depression, nausea/barfing, itching, even hallucinations). It is used generously to control pain postoperatively in the recovery room (new parlance: Post Anesthetic Care Unit), usually given 2 - 4 mg IV push at a time. It undergoes hepatic clearance.

Since IV push drugs are not allowed to be given by ward RNs in many hospitals (medicolegal stuff), morphine is often given intramuscularly (IM ) on regular wards (eg Morphine 10 mg IM q 3-4 h prn ).

Meperidine (brand name Demerol) is like morhpine but is synthetic and lasts a little less. Many patients prefer it over morphine (and vise versa). It is also less potent than morphine at about 1 morphine = 10 meperidine. Typical ward meperidine dosing is Meperidine 100 mg IM q 2-3 h prn.

Often morphine is given using Patient Contolled Analgesia machines.

Naloxone

Naloxone (Narcan, DuPont) is a specific narcotic (opiate) antagonist or antidote, kind of like "anti-morphine". By competitively displacing opiate molecules from opiate receptors, naloxone can often reverse the effect of a narcotic overdose in seconds (thus sometimes transforming a previously managable patient into an uncontrollable maniac and endangering the ER). I give 100 mcg (0.1 mg) IV push at a time; many others are more heavy handed. Also, remember that naloxone is not a long-lasting drug; it may need to be repeatedly given (or administered by infusion) in some settings.

Warnings: Can lead to intense cardiovascular stimulation and patient agitation. Has resulted in pulmonary edema. Leads to withdrawal in opiate addicts. Can transform a barely responsive emergency room patient into a violent, dangerous "madman".

Hepatic clearance.

Nitroglycerine

You may be most familiar with nitroglycerine in its tablet form in 0.3 and 0.6 mg strengths intended for sublingual use in the treatment of myocardial ischemia (angina, infarction). It is also used intravenously as an infusion in the coronary care unit to treat unstable angina (eg NTG 100 mg in 250 D5W at 10 to 40 ml/hr - appropriate dose may vary enormously).

Nitroglycerine (NTG) is used in obstetrical emergencies resulting from excessive uterine tone. In doses of 50 - 100 mcg (micrograms) IV push one can temporarily relax the uterus to handle situations such as trapping of the aftercoming head in a breech birth.

Hepatic and renal clearance.

Pepsid

I have never used this drug much, but it is quite popular anyway, being the latest and greatest in reducing stomach acidity. Generic name Famotidine.

Placebo

Placebos (eg, IV or IM saline) are often effective in the management of pain and anxiety, but are of dubious ethical propiety. Placebos are often given as part of prospective, blinded, randomized clinical trials, but informed consent requires that these patients know they may receive a placebo.

Propofol

This drug causes almost instant (one circulation time) general anesthesia when given IV push (e.g., 1-2.5 mg/kg). It is also popular for IV sedation for dental procedures or surgery under regional anesthesia (used at 20-100 mcg/kg/min for this purpose with appropriate respiratory monitoring)

Ranitidine

The successor to cimetidine, but with less complications, and so more popular. Results in reduced stomach acidity (higher gastric pH), important in reducing the danger that accidently aspirated gastric contents leads to aspiration pneumonitis.

Commonly used in the ICU setting to prevent stress ulcers. Usual oral dose 150 mg BID or 300 mg po HS; Usual ICU dose 50 mg q8H

Sodium Nitroprusside

This very potent, very fast-acting arterial vasodilator must be given with caution and with an in-dwelling arterial line in place. It belongs only in the OR / ICU / ER area of the hospital, and should be administed by volumetric infusion pump wherever possible. Usual range 0.5 to 10 mcg/kg/min. Beware of cyanide toxicity heralded by a metabolic acidosis with aggressive use. Excessive hypotensive / hypertensive swings which may occur with klutzy administration of sodium nitroprusside may require active correction (application of drugs) instead of mere passive correction (waiting out the hypotension). Brand name Nipride.

Sublimaze

see fentanyl

Succinylcholine

This is another dangerous drug. It stops skeletal muscle for working for several minutes or more (i.e., you are paralyzed). Imagine the trouble you can get into when you take away a patient's ability to breathe and then find that you are unable to manage the patient's airway. Succinylcholine is used mainly to facilitate tracheal intubation and should be used only by clinicians experienced in airway management. The typical dose is 1 to 1.5 mg / kg IV push. The effect lasts about 5-10 minutes, following clearance by plasma cholinesterase.

Since awake paralysis is extremely frightening even if the airway is managed correctly, muscle relaxants are ordinarily only administered to unconscious patients (eg, under general anesthesia).

Warning: There are many contraindications to succinylcholine which you must know for the exams.

Tagamet

see cimetidine

Tobramycin

Tobramycin and gentamycin are well-known aminoglycoside antibiotics particularly active against gram negative organisms. Aminoglycosides are sometimes ototoxic, causing damage to the eighth cranial nerve. (ICU survivors of sepsis sometimes develop deafness). Whereas opinion once held that aminoglycosides should be given with particular attention to keeping drug levels within a particular therapeutic window ("not too low; not too high"), consensus is not drifting towards once-a-day dosing with doses that would at once have been considered excessive.

Tranxemic Acid

Generic name for Cyclokapron

Thiopental

This cheap ultrashort-acting barbiturate causes almost instant general anesthesia in doses of 4-6 mg/kg IV push. It has lost market share to propofol (Diprivan). Doses of 50-100 mg IV push are sometimes needed to stop grand-mal seizures that don't respond to IV diazepam. This drug is used almost exclusively by anesthesiologists.

Verapamil

This calcium channel blocker is effective as an anti-anginal agent as well as in the treatment of some supraventricular arrhythmias. Usual dose 5 mg IV push. Must know your arrhythmias correctly to use this drug safely.

Zantac

see ranitidine