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Acetylcysteine


Pronunciation

 (a se teel SIS teen)


U.S. Brand Names

 Acetadote®; Mucomyst®


Synonyms

 Acetylcysteine Sodium; Mercapturic Acid; NAC; N -Acetylcysteine; N -Acetyl-L-cysteine


Generic Available

 Yes: Solution for inhalation


Canadian Brand Names

 Mucomyst®; Parvolex®


Use

 Adjunctive mucolytic therapy in patients with abnormal or viscid mucous secretions in acute and chronic bronchopulmonary diseases; pulmonary complications of surgery and cystic fibrosis; diagnostic bronchial studies; antidote for acute acetaminophen toxicity


Use - Unlabeled/Investigational

 Prevention of radiocontrast-induced renal dysfunction (oral); distal intestinal obstruction syndrome (DIOS, previously referred to as meconium ileus equivalent)


Pregnancy Risk Factor

 B


Pregnancy Implications

 Based on limited reports using acetylcysteine to treat acetaminophen overdose in pregnant women, acetylcysteine has been shown to cross the placenta and may provide protective levels in the fetus.


Lactation

 Excretion in breast milk unknown/use caution


Contraindications

 Hypersensitivity to acetylcysteine or any component of the formulation


Warnings/Precautions

Inhalation: Since increased bronchial secretions may develop after inhalation, percussion, postural drainage and suctioning should follow; if bronchospasm occurs, administer a bronchodilator; discontinue acetylcysteine if bronchospasm progresses

Intravenous: Acute flushing and erythema have been reported; usually occurs within 30-60 minutes and may resolve spontaneously. Serious anaphylactoid reactions have also been reported. Acetylcysteine infusion may be interrupted until treatment of allergic symptoms is initiated; the infusion can then be carefully restarted. Treatment for anaphylactic reactions should be immediately available. Use caution with asthma or history of bronchospasm.


Adverse Reactions

Inhalation: Frequency not defined.

Central nervous system: Drowsiness, chills, fever

Gastrointestinal: Vomiting, nausea, stomatitis

Local: Irritation, stickiness on face following nebulization

Respiratory: Bronchospasm, rhinorrhea, hemoptysis

Miscellaneous: Acquired sensitization (rare), clamminess, unpleasant odor during administration

Intravenous:

>10%: Miscellaneous: Anaphylactoid reaction (~17%; reported as severe in 1% or moderate in 10% of patients within 15 minutes of first infusion; severe in 1% or mild-to-moderate in 6% to 7% of patients after 60-minute infusion)

1% to 10%:

Cardiovascular: Angioedema (2% to 8%), vasodilation (1% to 6%), hypotension (1% to 4%), tachycardia (1% to 4%), syncope (1% to 3%), chest tightness (1%), flushing (1%)

Central nervous system: Dysphoria (<1% to 2%)

Dermatologic: Urticaria (2% to 7%), rash (1% to 5%), facial erythema ( 1%), palmar erythema ( 1%), pruritus ( 1% to 3%), pruritus with rash and vasodilation (2% to 9%)

Gastrointestinal: Vomiting (<1% to 10%), nausea (1% to 10%), dyspepsia ( 1%)

Neuromuscular & skeletal: Gait disturbance (<1% to 2%)

Ocular: Eye pain (<1% to 3%)

Otic: Ear pain (1%)

Respiratory: Bronchospasm (1% to 6%), cough (1% to 4%), dyspnea (<1% to 3%), pharyngitis (1%), rhinorrhea (1%), rhonchi (1%), throat tightness (1%)

Miscellaneous: Diaphoresis ( 1%)


Overdosage/Toxicology

 Treatment of acetylcysteine toxicity is usually aimed at reversing anaphylactoid symptoms or controlling nausea and vomiting. The use of epinephrine, antihistamines, and steroids may be beneficial.


Drug Interactions

 Adsorbed by activated charcoal; clinical significance is minimal, though, once a pure acetaminophen ingestion requiring N-acetylcysteine is established; further charcoal dosing is unnecessary once the appropriate initial charcoal dose is achieved (5-10 g:g acetaminophen)


Stability

Solution for injection (Acetadote®): Store vials at room temperature, 20°C to 25°C (68°F to 77°F); following reconstitution with D5W, solution is stable for 24 hours at room temperature

Note: To avoid fluid overload in patients <40 kg and those requiring fluid restriction, decrease volume of D5W proportionally. Discard unused portion.

Loading dose: Dilute 150 mg/kg in D5W 200 mL

Initial maintenance dose: Dilute 50 mg/kg in D5W 500 mL

Second maintenance dose: Dilute 100 mg/kg in D5W 1000 mL

Solution for inhalation (Mucomyst®): Store unopened vials at room temperature; once opened, store under refrigeration and use within 96 hours. The 20% solution may be diluted with sodium chloride or sterile water; the 10% solution may be used undiluted. A color change may occur in opened vials (light purple) and does not affect the safety or efficacy.

Intravenous administration of solution for inhalation (unlabeled route): Using D5W, dilute acetylcysteine 20% oral solution to a 3% solution.


Compatibility

Inhalation: Incompatible with rubber and metals (particularly iron, copper, and nickel); do not mix with ampicillin, tetracycline, oxytetracycline, erythromycin

Intravenous: Incompatible with rubber and metals (particularly iron, copper, and nickel)


Mechanism of Action

 Exerts mucolytic action through its free sulfhydryl group which opens up the disulfide bonds in the mucoproteins thus lowering mucous viscosity. The exact mechanism of action in acetaminophen toxicity is unknown; thought to act by providing substrate for conjugation with the toxic metabolite.


Pharmacodynamics/Kinetics

Onset of action: Inhalation: 5-10 minutes

Duration: Inhalation: >1 hour

Distribution: 0.47 L/kg

Protein binding, plasma: 83%

Half-life elimination:

Reduced acetylcysteine: 2 hours

Total acetylcysteine: Adults: 5.5 hours; Newborns: 11 hours

Time to peak, plasma: Oral: 1-2 hours

Excretion: Urine


Dosage

Acetaminophen poisoning: Children and Adults:

Oral: 140 mg/kg; followed by 17 doses of 70 mg/kg every 4 hours; repeat dose if emesis occurs within 1 hour of administration; therapy should continue until all doses are administered even though the acetaminophen plasma level has dropped below the toxic range

I.V. (Acetadote®): Loading dose: 150 mg/kg over 15 minutes. Maintenance dose: 50 mg/kg infused over 4 hours followed by 100 mg/kg infused over 16 hours. Note: To avoid fluid overload in patients <40 kg and those requiring fluid restriction, decrease volume of D5W proportionally.

Alternatively, the following dose has been reported using solution for oral inhalation (unlabeled): Loading dose: 140 mg/kg, followed by 70 mg/kg every 4 hours, for a total of 13 doses (loading dose and 48 hours of treatment); infuse each dose over 1 hour

Adjuvant therapy in respiratory conditions: Note: Patients should receive an aerosolized bronchodilator 10-15 minutes prior to acetylcysteine.

Inhalation, nebulization (face mask, mouth piece, tracheostomy): Acetylcysteine 10% and 20% solution (Mucomyst®) (dilute 20% solution with sodium chloride or sterile water for inhalation); 10% solution may be used undiluted

Infants: 1-2 mL of 20% solution or 2-4 mL of 10% solution until nebulized given 3-4 times/day

Children and Adults: 3-5 mL of 20% solution or 6-10 mL of 10% solution until nebulized given 3-4 times/day; dosing range: 1-10 mL of 20% solution or 2-20 mL of 10% solution every 2-6 hours

Inhalation, nebulization (tent, croupette): Children and Adults: Dose must be individualized; may require up to 300 mL solution/treatment

Direct instillation: Adults:

Into tracheostomy: 1-2 mL of 10% to 20% solution every 1-4 hours

Through percutaneous intrathecal catheter: 1-2 mL of 20% or 2-4 mL of 10% solution every 1-4 hours via syringe attached to catheter

Diagnostic bronchogram: Nebulization or intrathecal: Adults: 1-2 mL of 20% solution or 2-4 mL of 10% solution administered 2-3 times prior to procedure

Prevention of radiocontrast-induced renal dysfunction (unlabeled use): Adults: Oral: 600 mg twice daily for 2 days (beginning the day before the procedure); may be given as powder in capsules, some centers use solution (diluted in cola beverage or juice). Hydrate patient with saline concurrently.


Administration

Inhalation: Acetylcysteine is incompatible with tetracyclines, erythromycin, amphotericin B, iodized oil, chymotrypsin, trypsin, and hydrogen peroxide. Administer separately. Intermittent aerosol treatments are commonly given when patient arises, before meals, and just before retiring at bedtime.

Oral: For treatment of acetaminophen overdosage, administer orally as a 5% solution. Dilute the 20% solution 1:3 with a cola, orange juice, or other soft drink. Use within 1 hour of preparation. Unpleasant odor becomes less noticeable as treatment progresses. If patient vomits within 1 hour of dose, readminister.

I.V. administration of ORAL N-acetylcysteine: Recommended procedure:

Obtain informed consent.

Using D5W, dilute acetylcysteine 20% oral solution to a 3% solution.

Administer loading dose of NAC: 140 mg/kg infused through a peripheral intravenous catheter over 1 hour using an in-line 0.2- millipore filter

Administer maintenance doses of NAC (first maintenance dose 4 hours after initiating the loading dose): 70 mg/kg/dose: Doses administered every 4 hours, each infused over 1 hour through an in-line 0.2- millipore filter for a total of 13 doses (loading dose and 48 hours of treatment) treatment progresses.


Monitoring Parameters

 Acetaminophen overdose: AST, ALT, bilirubin, PT, serum creatinine, BUN, serum glucose and electrolytes. Acetaminophen levels at ~4 hours postingestion (~8 hours if extended release acetaminophen), and 4-6 hours later to assess for possible hepatotoxicity. Assess patient for nausea, vomiting, and skin rash following oral administration for treatment of acetaminophen poisoning.


Reference Range

 Determine acetaminophen level as soon as possible, but no sooner than 4 hours after ingestion (to ensure peak levels have been obtained); administer for acetaminophen level >150 mcg/mL at 4 hours following ingestion; toxic concentration with probable hepatotoxicity: >200 mcg/mL at 4 hours or 50 mcg at 12 hours


Patient Education

 Pulmonary treatment: Prepare solution (may dilute with sterile water to reduce concentrate from impeding nebulizer) and use as directed. Clear airway by coughing deeply before using aerosol. Wash face and face mask after treatment to remove any residual. You may experience drowsiness (use caution when driving), nausea, or vomiting (small, frequent meals may help). Report persistent chills or fever, adverse change in respiratory status, palpitations, or extreme anxiety or nervousness.


Anesthesia and Critical Care Concerns/Other Considerations

 The oral form of acetylcysteine has been given intravenously in acetaminophen overdose for a restricted number of indications (oral cannot be tolerated; coingested toxin requires ongoing gastrointestinal decontamination; gastrointestinal tract nonfunctional; late presentation of acetaminophen overdose; neonatal toxicity from maternal overdose) (Yip, 1998). The oral preparation is sterile, but not labeled "pyrogen free." In Yip's retrospective case series, adverse reactions occurred in 4 (~5%) cases. Flushing, pruritus, and phlebitis were reported; one was labeled as an "anaphylactic reaction." Bailey and McGuigan reviewed a retrospective case series of patients who received intravenous acetylcysteine and the literature to develop management guideline for anaphylactoid reactions (Bailey, 1998). Their recommendations for treatment of non-life-threatening allergic reactions include reassessing the need for intravenous acetylcysteine, and administering diphenhydramine (1 mg/kg I.V.; maximum dose: 50 mg). If the acetylcysteine infusion was stopped initially and symptoms resolved, consider restarting infusion 1 hour after diphenhydramine's administration. Monitor closely for allergic reactions. Be prepared to handle anaphylactoid reaction if it occurs.


Cardiovascular Considerations

 Although study results vary, acetylcysteine may be beneficial in prevention of radiocontrast-induced nephropathy in patients undergoing cardiac catheterization (Curhan, 2003). Tepel (2000) and his group originally randomized 83 patients with chronic renal insufficiency to oral acetylcysteine (600 mg twice daily) and intravenous saline 0.45% or placebo and intravenous saline 0.45%. All patients were having a CT scan with iopromide contrast. Patients receiving acetylcysteine had a significant reduction in serum creatinine 48 hours after the procedure. Conversely, patients in the placebo arm had significant increase in serum creatinine.

A recent randomized, placebo-controlled trial in 200 Chinese patients with stable mild-to-moderate renal insufficiency also evaluated acetylcysteine in prevention of radiocontrast-induced nephropathy (Kay, 2003). Patients were undergoing elective coronary angiography and/or intervention, and had serum creatinine concentrations >1.2 mg/dL or Clcr<60 mL/minute (estimated and measured). A low-osmolality nonionic contrast agent was used. All patients received saline 0.9% I.V. at 1 mL/kg/hour for 12 hours before and for 6 hours after contrast exposure. Three doses of acetylcysteine (600 mg twice daily) or matching placebo were given before and one dose after dye exposure. Contrast nephropathy developed more frequently in the control group (12%) than in the acetylcysteine group (4%). The average length of hospitalization was 0.5 days shorter in the acetylcysteine group. No adverse events related to acetylcysteine were reported.

However, these results differed from those in another prospective, randomized trial (Allaqaband, 2002) that compared the efficacy of acetylcysteine (600 mg twice daily for 48 hours) plus saline 0.45% versus fenoldopam (0.1 mcg/kg/minute) plus saline 0.45% versus saline 0.45% alone (at 1 mL/kg/hour for 12 hours before procedure, during procedure, and 12 hours afterwards) in preventing radiocontrast-induced nephropathy. Patients were high-risk (serum creatinine >1.6 mg/dL or Clcr<60 mL/minute) and undergoing cardiovascular procedures using low-osmolality nonionic contrast. Authors concluded that there was no benefit in either acetylcysteine or fenoldopam over saline in preventing radiocontrast-induced nephropathy. Parameters used to define radiocontrast-induced nephropathy varied among studies.


Dental Health: Effects on Dental Treatment

 Key adverse event(s) related to dental treatment: Stomatitis, drowsiness, fever, vomiting, nausea, bronchospasm, rhinorrhea, hemoptysis, and dizziness.


Dental Health: Vasoconstrictor/Local Anesthetic Precautions

 No information available to require special precautions


Mental Health: Effects on Mental Status

 May cause drowsiness


Mental Health: Effects on Psychiatric Treatment

 Sedative effects may be potentiated by psychotropic agents


Dosage Forms

Injection, solution (Acetadote®): 20% [200 mg/mL] (30 mL) [contains disodium edetate]

Solution, as sodium (Mucomyst®): 10% [100 mg/mL] (4 mL, 10 mL, 30 mL); 20% [200 mg/mL] (4 mL, 10 mL, 30 mL)


References

Allaqaband S, Tumuluri R, Malik AM, et al, "Prospective Randomized Study of N-Acetylcysteine, Fenoldopam, and Saline for Prevention of Radiocontrast-Induced Nephropathy," Catheter Cardiovasc Interv , 2002, 57(3):279-83.

Appelboam AV, Dargan PI, and Knighton J, "Fatal Anaphylactoid Reaction to N-Acetylcysteine: Caution in Patients With Asthma," Emerg Med J , 2002, 19(6):594-5.

Bailey B and McGuigan MA, "Management of Anaphylactoid Reactions to Intravenous N-Acetylcysteine," Ann Emerg Med , 1998, 31(6):710-5.

Curhan GC, "Prevention of Contrast Nephropathy," JAMA , 2003, 289(5):606-8.

Douglas D and Smilkstein M, "Deferoxamine-Iron Induced Pulmonary Injury and N-Acetylcysteine," J Toxicol Clin Toxicol , 1995, 33(5):495.

Falk JL, "Oral N-Acetylcysteine Given Intravenously for Acetaminophen Overdose: We Shouldn't Have To, But We Must," Crit Care Med , 1998, 26(1):7.

Harrison PM, Wendon JA, Gimson AE, et al, "Improvement by Acetylcysteine of Hemodynamics and Oxygen Transport in Fulminant Hepatic Failure," N Engl J Med , 1991, 324(26):1852-7.

Henderson A and Hayes P, "Acetylcysteine as a Cytoprotective Antioxidant in Patients With Severe Sepsis: Potential New Use for an Old Drug," Ann Pharmacother , 1994, 28(9):1086-8.

Kay J, Chow WH, Chan TM, et al, "Acetylcysteine for Prevention of Acute Deterioration of Renal Function Following Elective Coronary Angiography and Intervention: A Randomized Controlled Trial," JAMA , 2003, 289(5):553-8.

Keays R, Harrison PM, Wendon JA, et al, "Intravenous Acetylcysteine in Paracetamol Induced Fulminant Hepatic Failure: A Prospective Controlled Trial," BMJ , 1991, 303(6809):1026-9.

Mascarenhas MR, "Treatment of Gastrointestinal Problems in Cystic Fibrosis," Curr Treat Options Gastroenterol , 2003, 6(5):427-41.

Mohammed S, Jamal AZ, and Robison LR, "Serum Sickness-Like Illness Associated With N-Acetylcysteine Therapy," Ann Pharmacother , 1994, 28(2):285.

Mokhlesi B, Leikin JB, Murray P, et al, "Adult Toxicology in Critical Care: Part II: Specific Poisonings," Chest , 2003, 123(3):897-922.

Mroz L, Benitez JG, and Krenzelok E, "Angioedema With Oral Acetylcysteine," Clin Toxicol , 1995, 33(5):554-5

Prescott LF, Donovan JW, Jarvie DR, et al, "The Disposition and Kinetics of Intravenous N-acetylcysteine in Patients With Paracetamol Overdosage," Eur J Clin Pharmacol , 1989, 37(5):501-6.

Rodgers G, Matyunas N, Ross M, et al, "Sulfhemoglobinemia Associated With N-Acetylcysteine (NAC) Therapy of Acetaminophen (APAP) Overdose: A Case Report," Clin Toxicol , 1995, 33(5):530.

Smilkstein MJ, Knapp GL, Kulig KW, et al, "Efficacy of N-Acetylcysteine in the Treatment of Acetaminophen Overdose: Analysis of the National Multicenter Study (1976 to 1985)," N Engl J Med , 1988, 319(24):1557-62.

Tepel M, van der Giet M, Schwarzfeld C, et al, "Prevention of Radiographic-Contrast-Agent-Induced Reductions in Renal Function by Acetylcysteine," N Engl J Med , 2000, 343(3):180-4.

Walson PD and Groth JF Jr, "Acetaminophen Hepatotoxicity After Prolonged Ingestion," Pediatrics , 1993, 91(5):1021-2.

Woo OF, Anderson IB, Kim SY, et al, "Shorter Duration of N-Acetylcysteine (NAC) for Acute Acetaminophen Poisoning," Clin Toxicol , 1995, 33(5):508.

Yankaskas JR, Marshall BC, Sufian B, et al, "Cystic Fibrosis Adult Care: Consensus Conference Report," Chest , 2004, 125(1 Suppl):1-39.

Yip L, Dart RC, and Hurlbut KM, "Intravenous Administration of Oral N-Acetylcysteine," Crit Care Med , 1998, 26(1):40-3.


International Brand Names

 ACC® (AT, CZ, DE, HU, LU, MX, PL, RO, ZA); ACC eco® (CH); ACC Hexal® (AT); ACC Hot® (PL); ACC® Injectabil (RO); ACC injekt® (RU); Acemuc® (DE); Acemucol® (CH); Acemuk® (AR); Acetabs® (DE); Acetaps® (DE); Acetein® (JP); Acetilcisteina Bexal® (ES); Acetilcisteina® (ES, RO); Acetilcisteina Farmasierra® (ES); Acetilcisteina Hexan® (IT); Acetilcisteina Pantofarm® (ES); Acetilcisteina Ratiopharm® (ES, IT); Acetin® (TH); Acetylcistein von CT® (RO); Acetylcystein AstraZeneca® (SE); Acetylcystein Atid® (DE); Acetylcystein-Cophar® (CH); Acetylcysteine EG® (BE); Acetylcysteine® (LU); Acetylcysteine-ratiopharm® (BE); Acetylcystein Genericon® (AT); Acetylcystein Helvepharm® (CH); Acetylcystein Heumann® (DE); Acetylcystein NM Pharma® (SE); Acetylcystein Nycomed® (AT); Acetylcystein Ratiopharm® (DE); Acetylcystein Trom® (DE, TR); Acetyphar® (BE); Acetyst® (DE); AC-Pulmin® (HU); Acypront® (EC, PL); Aeromuc® (AT); Aflux® (CO); Altersol® (IT); Asist® (TR); Atse® (DE); Azubronchin® (DE); Bisolapid® (CH); Bisolbruis® (NL); Bromuc® (DE); Broncholysin® (CZ); Broncoclar® (FR); Broncolar® (FR); Bronkyl® (NO); Brunac® (HR, IT); Cimexyl® (AT); Dampo Mucopect® (NL); DemoLibral® (CH); Drenaflen® (EC); durabronchal® (DE); Dynamucil® (CH); Ecomucyl® (CH); Ecomucyl® [inj.] (CH); Euronac® (MC); Exomuc® (FR, LU, RU); Flemex-AC® (TH); Flouidouche® (CH); Flucil-EF® (TH); Flucil® (TH); Fluidouche® (CH); Fluimiquil® (LU); Fluimucil Antidote® (PL); Fluimucil Antidoto® (ES); Fluimucil® (AR, AT, BR, CH, CO, DE, EC, ES, FR, HK, HU, ID, IT, NL, PL, PT, RO, RU, SG, TH, YU); Fluimukan® (HR, RO, SI); Flumil® (ES); Génac® (FR); Genac® (RO); Granon® (DK); Hidonac® (IT, RO); Hoestil® (NL); L-Cimexyl® (CH, CZ, HK); Libramucil® (EC); Librochin acetylcysteine® (NL); Lindolys® (DE); Locomucil® (ES); Lubrisec® (AR); Lysomucil® (BE, LU); Lysox® (BE, LU); Mentopin® (HU, TR); M-Pectil® (NL); Mucil® (TH); Mucisol® (IT); Muciteran® (DE); Mucobene® (AT, CZ); Mucocil® (NL, TH); Mucofial® (IT); Mucofluid® (CH); Mucolair® (BE, LU); Mucolator® (BE, FR, HK, LU); Mucolitico® (CL); Mucolysin® (DK); Muco-Mepha® (CH); Mucomix® (IN); Mucomyst® (AT, AU, BE, CA, DK, FI, FR, IL, LU, NL, NO, SE); Mucoporetta® (FI); Mucospire® (FR); Mucostop® (CH); Mucotic® (TH); Mucovim® (RO); Mucoxan® (IT); Mucoza® (TH); Mucret® (DE); Mu-Off® (HK); Mysoven® (TH); Myxofat® (DE); NAC 1 A Pharma® (DE); NAC AbZ® (DE); NAC AL® (CZ, DE, HU); N-Acetilcisteina EG® (IT); N-Acetilcisteina Pliva® (IT); NAC-findusFit® (DE); NAC-Hemofarm® (YU); NAC-Hemopharm® (DE); NAC Klast® (DE); Nac Long® (TH); NAC-ratiopharm® (DE, LU); NAC Sandoz® (DE); NAC-Stada® (DE); Nactop® (BE); NAC von ct® (DE); NeoCitran Hustenl&ouml;ser® (CH); Oxxa® (TR); Parvolex® (AU, CA, GB, NZ); Pectomucil® (BE, LU); Phamug® (DE); Pharcetil® (BE, NL); Pulmovent® (AT); Rinofluimucil® (CO); Robitussin Expectorant® (CH); Rumicil® (LU); Secresol® (CH); Siccoral® (AT); Siran® (DE, ID, IL, RO); Solmucol® (CH, CZ, ES, FR, HU, IT, LU, SG, ZA); Solv-AC T® (HU); Sputopur® (HU); Syntemucol® (PL); Tirocular® (IT, PT); Tixair® (FR); Touxium Mucolyticum® (BE, LU); Tussicom® (PL); Ultraflu® (IT); Viskoferm® (SE); Zifluvis® (CO)


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