Asmaphen Syrup, Tablet

Pseudoephedrine is both an α-and β-adrenergic receptor agonist. It causes vasoconstriction via direct stimulation of α-adrenergic receptors of the respiratory mucosa. It also directly stimulates β-adrenergic receptors causing bronchial relaxation, increased heart rate and contractility.

Like ephedrine, pseudoephedrine releasing norepinephrine from its storage sites, an indirect effect. This is its main and direct mechanism of action. The displaced noradrenaline is released into the neuronal synapse where it is free to activate the postsynaptic adrenergic receptors.


Pseudoephedrine is a decongestant of the mucous membranes of the upper respiratory tract, especially the nasal mucosa, sinuses and eustachian tube. It is used for the symptomatic relief of allergic rhinitis (hay fever), vasomotor rhinitis, the common cold, influenza (flu) and ear congestion caused by ear inflammation or infection. Pseudoephedrine can also be used as a bronchodilator.

Pseudoephedrine is a stereoisomer of Asmaphen with similar but less potent pharmacological activity. It has nasal and bronchial decongestant activity.

Asmaphen is also used to associated treatment for these conditions: Allergic Disorder, Bronchial Asthma, Common Cold, Cough, Depression, Fever, General Anesthesia Induced Hypotension, Headache, Joint Pain, Myasthenia Gravis, Narcolepsy, Nasal Congestion, Rhinorrhoea, Sore Throat, Dry cough

Trade Name Asmaphen
Generic Ephedrine
Other Names Efedrina, Ephedrine, L-Ephedrine
Weight 15mg/5ml, 30mg
Type Syrup, Tablet
Formula C10H15NO
Weight Average: 165.2322
Monoisotopic: 165.115364107
Protein binding

(-) Ephedrine is 4.9±0.3% bound to human serum albumin and (+) Ephedrine is 6.9±1.4% bound to human serum albumin.

Therapeutic Class Decongestant
Manufacturer Seema Pharmaceuticals Ltd
Available Country Bangladesh
Last Updated: June 23, 2021 at 11:20 am


Asmaphen dosage

As a decongestant and symptomatic treatment for upper respiratory tract infections the recommended dose is:

Adults: 1 tablet every 4 to 6 hours, up to maximum of 240 mg in 24 hours


  • 6-12 years of age: 1/2 tablet every 4 to 6 hours daily
  • 2-5 years of age: 1/4 tablet every 4 to 6 hours daily
  • Less than 2 years of age: This drug is not advised unless specifically recommended by a physician.

Side Effects

Serious adverse effects associated with the use of Pseudoephedrine are rare. Symptoms of central nervous system excitation may occur, including sleep disturbances and, rarely, hallucinations have been reported. Skin rashes, with or without irritation, have occasionally been reported.


Although Pseudoephedrine has virtually no pressor effects in normotensive patients, it should be used with caution in patients suffering mild to moderate hypertension. As with other sympathomimetic agents, Pseudoephedrine should be used with caution in patients with hypertension, heart disease, diabetes, hyperthyroidism, elevated intraocular pressure and prostatic enlargement. Caution should be exercised when using the product in the presence of severe hepatic impairment or moderate to severe renal impairment.

Food Interaction

No interactions found.

Volume of Distribution

Oral ephedrine has an average volume of distribution of 215.6L.

Half Life

Oral ephedrine has a plasma elimination half life of approximately 6 hours, but there is a large degree of inter-patient variability.


Oral ephedrine has a clearance of 23.3L/h but there is a high degree of inter-patient variability.

Pregnancy & Breastfeeding use

Although Pseudoephedrine has been in widespread use for many years without apparent ill consequence, there are no specific data on its use during pregnancy. Caution should therefore be exercised by balancing the potential benefit of treatment to the mother against any possible hazards to the developing foetus. Pseudoephedrine is excreted in breast milk in small amounts but the effect of this on breast-fed infants is not known.


Pseudoephedrine is contraindicated in-

  • Hypersensitivity of individuals to this drug
  • Severe hypertension and coronary artery disease
  • Concurrent use of Mono Amine Oxidase Inhibitor (MAOI) drugs

Acute Overdose

As with other sympathomimetic agents, symptoms of overdosage include irritability, restlessness, tremor, convulsions, palpitations, hypertension and difficulty in micturition. Necessary measures should be taken to maintain and support respiration and control convulsions. Gastric lavage should be performed if indicated. If desired, the elimination of Pseudoephedrine can be accelerated by acid diuresis or by dialysis.

Asmaphen contains Ephedrine see full prescribing information from innovator Monograph