Ephedrine
Ephedrine
International Programme on Chemical Safety
Poisons Information Monograph 209
Pharmaceutical
1. NAME
1.1 Substance
Ephedrine
1.2 Group
1.3 Synonyms
Ephedrinum;
Hydrated ephedrine,
Eedrynum hidratum;
Ephedrina;
Ma-huang;
1.4 Identification numbers
1.4.1 CAS
229-42-3 (anhydrous)
1.4.2 Other numbers
50906-05-3 (hemihydrate)
ATC codes: R01AA03
S01FB02
1.5 Main brand names
Amidrin; Daral; Fluidin; Kidargol; Rhinamide; Tedral;
Tenfril; Vicks decongestive cough syrup
1.6 Main manufacturers and/or importers
Farmacéutica Uruguaya
Lab. Andrómaco
Roussel-Labur
2. SUMMARY
2.1 Main risks and target organs
Cardiovascular: heart and arterial vessels
CNS stimulation
Chronic use can lead to tolerance with dependence
2.2 Summary of clinical effects
Digestive disorders: nausea, vomiting.
Cardiovascular impairment: tachycardia, severe hypertension
and secondary myocardial infarction and/or stroke.
Central effects: anxiety, tremor, irritability,
hallucinations, psychotic states, seizures, intracerebral
haemorrhage.
Metabolic dysfunction: hyperglycaemia, hypokalaemia
(intracellular shift).
2.3 Diagnosis
Diagnosis is based on history and/or the presence of
nausea, vomiting, tachycardia, headache, elevated blood
pressure. Ephedrine and its metabolites can be analyzed in
blood and urine by gas chromatography.
2.4 First aid measures and management principles
Gastrointestinal decontamination
Supportive and symptomatic care; administration of
propranolol in patients with severe arterial
hypertension.
3. PHYSICO-CHEMICAL PROPERTIES
3.1 Origin of the substance
Ephedra species (particularly E. sinica) contain chiefly
two alkaloids: ephedrine and pseudoephedrine, which is a
stereoisomer of ephedrine. Ephedra species have been used as
a source of ephedrine; ephedrine is also prepared
synthetically.
Ephedra is sold as a traditional Chinese medicinal herb under
the name Ma-huang.
(Parfitt, 1999)
3.2 Chemical structure
Molecular formula:
C10 H15 NO1
Molecular mass: 165.2
Structural name:
(1R,2S)-2-methylamino-1-phenylpropan-1-ol
3.3 Physical properties
3.3.1 Colour
Colourless or white
3.3.2 State/form
Solid-crystals
Solid-powder
3.3.3 Description
Bitter taste; odourless or slight aromatic
odour. In warm weather it slowly volatilizes. The
anhydrous substance melts at 36°C and the hemihydrate
melts at 42°C. It is a weak base, with a pKa = 9.6
Ephedrine decomposes with light. Solutions in oil can
have a garlicky odour. It is soluble in water (1 in
20) and in alcohol, chloroform, ether, glycerol, olive
oil and in liquid paraffin (Windholz, 1983).
Ephedrine and its optical isomer pseudoephedrine are
structurally very similar to methamphetamine. In
illicit drug laboratories simple dehydrogenation is
used to make methamphetamine from ephedrine (Kelley
1998).
3.4 Other characteristics
3.4.1 Shelf-life of the substance
3.4.2 Storage conditions
Protect from light.
Temperatures must not exceed 8EC in containers.
4. USES
4.1 Indications
4.1.1 Indications
4.1.2 Description
The most important uses are:
- as a bronchodilator
- nasal decongestant
- other uses: syndrome of Stokes-Adams; as a
mydriatic and hypertensor in the
spinal-anesthesia. It is also used as
an herbal diet supplement under the
name "Ma-huang" as an anorectic and
CNS stimulant.
4.2 Therapeutic dosage
4.2.1 Adults
15 to 60 mg of ephedrine hydrochloride or
sulphate 3 or 4 times daily as a bronchodilator
4.2.2 Children
500 (g/kg body weight of ephedrine
hydrochloride or sulphate 3 or 4 times daily (Parfitt,
1999).
4.3 Contraindications
Cardiovascular disease; hypertension; hyperthyroidism;
phaeochromocytoma and closed angle glaucoma. Ephedrine
should not be given in patients being treated with MAOI (or
have stopped treatment in the last 14 days) (Dukes, 1988;
Parfitt, 1999; Dawson et al., 1995). It should be used with
caution in patients with prostatic enlargement or with renal
impairment
5. ROUTES OF EXPOSURE
5.1 Oral
Abuse of ephedrine-containing diet pills is a common
occurrence (MMWR, 1996).
5.2 Inhalation
Ephedrine salts are used as nasal drops or sprays in the
relief of nasal congestion associated with cold or rhinitis.
Ephedrine can be abused by the nasal route by subjects who
have developed dependence to its vasoconstrictive effect
(Bismuth, 2000).
5.3 Dermal
As an ointments well absorbed.
5.4 Eye
Eye-drops at 0.1% are effective in congestion of
conjunctival allergy.
5.5 Parenteral
Subcutaneous or intramuscular injections.
5.6 Other
6. KINETICS
6.1 Absorption by route of exposure
Ephedrine is readily and completely absorbed from the
gastrointestinal tract; plasma peak concentrations are
reached an hour after ingestion
A single oral dose of 24 mg produced an average peak plasma
concentration of 0.10 mg/L (Goldfrank, 1990).
6.2 Distribution by route of exposure
The volume of distribution is about 3L/kg; patients with
toxicity are not good candidates for haemodialysis (Kelley
1998).
6.3 Biological half-life by route of exposure
It has a plasma half-life ranging from 3 to 6 hours
depending on urinary pH (Parfitt, 1999).
No change in half-life from that seen with therapeutic dosing
was observed in an otherwise healthy patient with massive
overdose (Snook et al., 1992).
The ephedrine concentrations in three fatalities were 3.49;
7.85 and 20.5 mg/L (Ellenhorn, 1988).
6.4 Metabolism
Only a small amount of ephedrine is metabolized in the
liver.
6.5 Elimination by route of exposure
It is largely excreted unchanged in the urine, with some
deaminated metabolites and N-demethylated metabolites.
Elimination is enhanced in acid urine.
(Parfitt, 1999)
Less than 10% of ephedrine is excreted as norephedrine. In
normal subjects 70-80% of a dose is eliminated unchanged in
the urine within 48 hours. 4% is present as norephedrine
(Baselt and Cravey 1995)
7. PHARMACOLOGY AND TOXICOLOGY
7.1 Mode of action
7.1.1 Toxicodynamics
Ephedrine can produce stimulation at the
adrenergic receptors and neuronal norepinephrine
release (Kelley 1998).
7.1.2 Pharmacodynamics
Ephedrine has both alpha- and beta-adrenergic
activities, and both direct and indirect effects on
receptors. It raises blood pressure both by increasing
cardiac output and inducing peripheral
vasoconstriction (Shufman et al., 1994; Parfitt,
1999).
It can produce bronchodilation. In local application
it causes pupils dilation. The main metabolic effects
in overdose are hyperglycaemia and hypokalaemia.
Ephedrine is a centrally acting respiratory stimulant
and can increase motor activity.
7.2 Toxicity
7.2.1 Human data
7.2.1.1 Adults
The ephedrine concentrations in
three fatalities were 3.49, 7.85, and
20.5mg/L (Kelley 1998). However survival at
levels of 23mg/L has been reported (Baselt
and Cravey 1995)
7.2.1.2 Children
7.2.2 Relevant animal data
7.2.3 Relevant in vitro data
7.3 Carcinogenicity
No data available
7.4 Teratogenicity
No data available
7.5 Mutagenicity
No data available
7.6 Interactions
A serotonin syndrome has been reported in a patient
taking paroxetine and an over-the-counter cold medicine
containing ephedrine (Skop et al., 1994).
Combination of ephedrine and a MAOI can produce
life-threatening reactions (Dawson et al., 1995). It should
also be avoided in patients undergoing anaesthesia with
cyclopropane, halothane or other volatile anaesthesia. An
increased risk of arrhythmias may occur if given to patients
receiving cardiac glycosides, quinidine or tricyclic
antidepressants, ergot alkaloids, oxytocin (Parfitt
1999).
7.7 Main adverse effects
Central effects of sympathomimetic agents include:
tremor, fear, anxiety, confusion, irritability, insomnia, and
psychotic states. Paranoid psychosis, delusions and
hallucinations may also follow ephedrine overdose.
Effects on the cardiovascular system are complex:
vasoconstriction, hypertension, or hypotension and
bradycardia, tachycardia, palpitations, cardiac arrest.
It can cause local ischaemia in chronic topical use (Parfitt,
1999).
8. TOXICOLOGICAL ANALYSES AND BIOMEDICAL INVESTIGATIONS
8.1 Material sampling plan
8.1.1 Sampling and specimen collection
8.1.1.1 Toxicological analyses
8.1.1.2 Biomedical analyses
8.1.1.3 Arterial blood gas analysis
8.1.1.4 Haematological analyses
8.1.1.5 Other (unspecified) analyses
8.1.2 Storage of laboratory samples and specimens
8.1.2.1 Toxicological analyses
8.1.2.2 Biomedical analyses
8.1.2.3 Arterial blood gas analysis
8.1.2.4 Haematological analyses
8.1.2.5 Other (unspecified) analyses
8.1.3 Transport of laboratory samples and specimens
8.1.3.1 Toxicological analyses
8.1.3.2 Biomedical analyses
8.1.3.3 Arterial blood gas analysis
8.1.3.4 Haematological analyses
8.1.3.5 Other (unspecified) analyses
8.1.3.6
8.2 Toxicological analyses and their interpretation
8.2.1 Tests on toxic ingredient(s) of material
8.2.1.1 Simple qualitative test(s)
8.2.1.2 Advanced qualitative confirmation test(s)
8.2.1.3 Simple quantitative method(s)
8.2.1.4 Advanced quantitative method(s)
8.2.2 Tests for biological specimens
8.2.2.1 Simple qualitative test(s)
8.2.2.2 Advanced qualitative confirmation test(s)
8.2.2.3 Simple quantitative method(s)
8.2.2.4 Advanced quantitative method(s)
8.2.2.5 Other dedicated method(s)
8.2.3 Interpretation of toxicological analyses
8.3 Biomedical investigations and their interpretation
8.3.1 Biochemical analysis
8.3.1.1 Blood, plasma or serum
"Basic analyses"
"Dedicated analyses"
"Optional analyses"
8.3.1.2 Urine
"Basic analyses"
"Dedicated analyses"
"Optional analyses"
8.3.1.3 Other fluids
8.3.2 Arterial blood gas analyses
8.3.3 Haematological analyses
"Basic analyses"
"Dedicated analyses"
"Optional analyses"
8.3.4 Interpretation of biomedical investigations
8.4 Other biomedical (diagnostic) investigations and their
interpretation
8.5 Overall interpretation of all toxicological analyses and
toxicological investigations
9. CLINICAL EFFECTS
9.1 Acute poisoning
9.1.1 Ingestion
Early clinical manifestations of ingestion of
high doses of ephedrine consist of nausea and
vomiting, followed by insomnia, cardiac arrhythmia,
myocardial ischemia, agitation, psychosis and
seizures.
9.1.2 Inhalation
No data available
9.1.3 Skin exposure
No data available
9.1.4 Eye contact
No data available
9.1.5 Parenteral exposure
The parenteral use of ephedrine may cause
intracerebral haemorrhage as a result of a rise in
arterial pressure. Ventricular arrhythmias have been
described (Ellenhorn 1988).
9.1.6 Other
9.2 Chronic poisoning
9.2.1 Ingestion
Neurological symptoms that have been described
include headache, anxiety, tremor, insomnia,
dizziness, seizures (MMWR, 1996). Several cases of
psychosis have been reported (Roxanas & Spalding,
1977; Shufman et al., 1994; Copwell, 1995; Doyle &
Kargin, 1996; Jacobs & Kirsch, 2000).
Cardiovascular disorders associated with the chronic
use of ephedrine may include chest pain, hypertension,
arrhythmia, myocardial infarction, cerebral vascilitis
and stroke (MMWR, 1996).
9.2.2 Inhalation
No data available
9.2.3 Skin exposure
Local applications of ephedrine may cause
contact dermatitis (Tomb et al., 1991).
9.2.4 Eye contact
No data available.
9.2.5 Parenteral exposure
The intravenous use of ephedrine causes similar
effects as oral ingestion.
9.2.6 Other
The vasoconstrictive effects of ephedrine
applied topically as nasal spray or drops may cause
local ischaemia (Parfitt, 1999).
9.3 Course, prognosis, cause of death
Early clinical manifestations of ephedrine overdose
consist of nausea and vomiting, followed by headache,
agitation, anxiety, tremor, seizures, tachycardia and
hypertensive crisis. Severe rise in blood pressure may
produce cerebral haemorrhage and myocardial infarction.
Ventricular arrhythmia may progress to cardiac arrest and
death. Although fatalities have been reported the prognosis
is usually good (Burkhart, 1992; Snook et al., 1992; MMWR,
1996; Backer et al., 1997; Theoharides, 1997; Hedetoft et
al., 1999).
9.4 Systematic description of clinical effects
9.4.1 Cardiovascular
The most common symptoms are arterial
hypertension and tachycardia; ventricular arrhythmia,
chest pain, myocardial infarction, ischaemic or
haemorrhagic stroke, cardiac arrest may rarely occur
(Burkhart, 1992; Snook et al., 1992; MMWR, 1996;
Parfitt, 1999; Matthews et al., 1997; Hedetoft et al.,
1999)
9.4.2 Respiratory
Respiratory stimulation, bronchodilation,
pulmonary oedema apnea (Parfitt, 1999).
9.4.3 Neurological
9.4.3.1 CNS
CNS stimulation: anxiety, agitation,
tremor, mental confusion, hallucinations,
mania, paranoid psychosis may occur;
convulsions have been reported.
(Roxanas & Spalding, 1977; Snook et al.,
1992; Shufman et al., 1994; Copwell, 1995;
Doyle & Kargin, 1996; Jacobs & Kirsch,
2000).
9.4.3.2 Peripheral nervous system
No data available.
9.4.3.3 Autonomic nervous system
Ephedrine causes stimulation of the
sympathetic nervous system acting on both
alpha and beta receptors. Symptoms include
tachycardia, arterial hypertension, tremor,
sweating, mydriasis.
9.4.3.4 Skeletal and smooth muscle
Ephedrine produces relaxation of
smooth muscle. In overdose it may also cause
rhabdomyolysis (Salmon and Nicholson
1988)
9.4.4 Gastrointestinal
Nausea and vomiting are common.
9.4.5 Hepatic
No data available.
9.4.6 Urinary
9.4.6.1 Renal
No data available.
9.4.6.2 Other
Ephedrine relaxes the vesical
detrusor muscle, and increases contraction of
the vesical sphincter (alpha agonist action),
and can produce acute retention of urine
(Parfitt, 1999).
9.4.7 Endocrine and reproductive systems
Inhibition of insulin secretion.
9.4.8 Dermatological
No data available
9.4.9 Eye, ear, nose, throat: local effects
Chronic administration of nasal drops or spray
can result in rebound nasal congestion and rhinorrhoea
(Parfitt, 1996; Bismuth, 2000).
9.4.10 Haematological
Leukopenia.
9.4.11 Immunological
No data available.
9.4.12 Metabolic
9.4.12.1 Acid base disturbances
Metabolic acidosis.
9.4.12.2 Fluid and electrolyte disturbances
Hypokalaemia resulting from
intracellular shift.
9.4.12.3 Others
Hyperglycaemia.
9.4.13 Allergic reactions
Contact dermatitis after local application.
Sensitization and systemic allergic reactions (severe
eczema) have been reported after oral administration
(Audicana et al., 1991; Tomb et al., 1991).
9.4.14 Other clinical effects
9.4.15 Special risks
Ephedrine is present in breast-milk in
sufficient concentrations to be harmful to the baby,
and is contraindicated in women who are
breast-feeding. Patients with ischaemic heart disease,
hypertension, acute angle glaucoma, hyperthyroidism,
prostatic enlargement, or taking MAOI antidepressants
should also avoid ephedrine.
9.5 Other
Chronic use can lead to tolerance with dependence.
Ephedrine abuse is a common occurrence and has been
associated with several deaths (Roxanas & Spalding, 1977;
Copwell, 1995; Doyle & Kargin, 1996; Gualtieri & Harris,
1996; MMWR, 1996; Theoharides, 1997; Jacobs & Kirsch,
2000).
9.6 Summary
10. MANAGEMENT
10.1 General principles
Establish airway patency, breathing and circulation.
Establish baseline blood pressure and pulse.
Treatment is primarily supportive.
ECG monitoring is necessary. Monitor urine output.
Gastrointestinal decontamination may be indicated
There is no antidote.
10.2 Life supportive procedures and symptomatic/specific treatment
Severe hypertension and tachycardia should be treated
with the intravenous administration of a short-acting,
selective beta-blocker such as esmolol (Burkhart, 1992;
Bismuth, 2000). (Care should be taken as hypertension may be
aggrevated with use of beta-blockers owing to unopposed
alpha-agonist effects). Alternative treatments for
hypertension include nitroprusside or nitroglycerin infusion
In the treatment of ventricular dysrhythmias, lidocaine or
bretylium may be required.
Convulsions require administration of intravenous
diazepam.
10.3 Decontamination
Gastric lavage may be performed within 2 hours of
ingestion but can also increase intracranial pressure. Emesis
is contra-indicated
Administration of activated charcoal.
10.4 Enhanced elimination
Maintenance of adequate urine output is essential;
although ephedrine elimination is best achieved in acidic
urine, however the risk of this procedure in this setting
probably outweighs the potential benefits (Kelley 1998);
there is no evidence of the usefulness of forced diuresis,
hemodialysis or peritoneal dialysis in enhancing ephedrine
elimination.
10.5 Antidote treatment
10.5.1 Adults
10.5.2 Children
10.6 Management discussion
11. ILLUSTRATIVE CASES
11.1 Case reports from literature
A 20 y-o woman ingested 300 diet pills containing a
total of 7.5 g of ephedrine in a suicide attempt. She
presented to the ED two hours post ingestion, with a HR of
116, BP 146-60 mmHg, she was agitated and anxious, with
tremor and vomiting. Treatment included gastric lavage,
activated charcoal, and 1 mg propranolol. Serum ephedrine
level was 22.8 nanog/mL (therapeutic range: 0.04-0.08
nanog/mL) at 90 minutes post ingestion. The patient made an
uneventful recovery (Snook et al., 1992).
After ingesting 17500 mg of ephedrine, a 29 y-o female
developed a BP of 168-106. Her BP was 124-90 five minutes
after IV propranolol (Burkhart, 1992).
A 19 y-o woman ingested 1000 mg of ephedrine in combination
with 10000 mg of caffeine. She developed severe toxic
manifestations from the heart, CNS, muscles, liver and
kidneys leading to multiorgan failure, cardiac arrests and
died subsequently of cerebral oedema on the fourth day of
hospitalization (Hedetoft et al., 1999).
A 57 y-o woman had been taking a usual dose of ephedrine for
bronchial asthma (50 mg 3 times a day) for more than 30
years. When her husband died she developed depression, for
which she tried to use ephedrine as an antidepressant,
increasing the dose to 500 to 1000 mg a day over the course
of half a year. She developed paranoid psychosis with
delusions of persecution and auditory hallucinations.
Recovery was rapid after ephedrine was gradually reduced to
200 mg a day (Shufman et al., 1994)
12. ADDITIONAL INFORMATION
12.1 Specific preventive measures
12.3 Other
13. REFERENCES
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drugs. Contact Dermatitis, 24: 223
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chemicals in man. 4th Edition. Pub Chemical Toxicology Institute,
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Paris
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after sympathomimetic overdose: two case reports. J Toxicol Clin
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Dawson JK, Earnshaw SM, Graham CS (1995) Dangerous monoamine
oxidase inhibitor interactions are still occurring in the 1990's.
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Hedetoft C, Jensen CH, Christensen MR, Christensen O (1999) Fatal
poisoning with Letigen. Ugeskr Laeger, 161: 6937-6938
Jacobs KM & Kirsch KA (2000) Psychiatric complications of
Ma-huang. Psychosomatics, 41: 58-62
Kelley MT (1998). Chapter 39 Sympathiomimetics. In Clinical
Management of Poisioning and Drug Overdose 3rd Edition. Eds
Haddad, Shannon, Winchester. Pub WB Saunders Company Philidelphia,
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Salmon J, Nicholson D. DIC and rhabdomyolysis following
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Shufman NE, Witztum E, Vass A (1994) Ephedrine psychosis.
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cold remedy and vascular disease. Am J Emerg Med, 12: 642-644
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report and toxicokinetic analysis. Vet Human Toxicol, 34: 335
(abstract)
Theoharides TC (1997) Sudden death of a healthy college student
related to ephedrine toxicity from a Ma-huang-containing drink. J
Clin Psychopharmacol, 17: 437-439
Tomb RR, Lepoittevin JP, Espinassouze F, Heid E, Foussereau J
(1991) Systemic contact dermatitis from pseudoephedrine, Contact
Dermatitis, 24: 86-88
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Co., Inc.
14. AUTHOR(S), REVIEWER(S) DATA (INCLUDING EACH UPDATING), COMPLETE
ADDRESSES
Author: Dr Mabel Burger
Address: CIAT - Piso 7E
Hospital de Clinicas
Avenida Italia s/n
Montevideo
Uruguay
Tel: (598 2) 80 40 00
(598 2) 47 03 00
Fax: (598 2) 47 03 00
Date: July 1991
Update: MO Rambourg Schepens, September 2000
Reviewed at INTOX 12, Erfurt, Germany, November 2000
Reviewers M. Balali-Mood, W. Temple, B. Groszek, N. Langford.