Because of its pseudoephedrine content, this product may partially reverse the hypotensive action of drugs which interfere with sympathetic activity including bretylium, betanidine, guanethidine, debrisoquine, methyldopa, alpha- and beta- adrenergic blocking agents, [See Special Warnings and Special Precautions for Use].

4.6 Pregnancy and lactation
Insufficient information is available on the effects of administration of this product during human pregnancy. This product, like most medicines, should not be used during pregnancy unless the potential benefit of treatment to the mother outweighs the possible risks 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. It has been estimated that approximately 0.5 to 0.7 % of a single 60 mg dose of pseudoephedrine ingested by a nursing mother will be excreted in the breast milk over 24 hours.

Guaifenesin is excreted in breast milk in small amounts with no effect expected on the infant.
4.7 Effects on ability to drive and use machines
No special comment - unlikely to produce an effect.

4.8 Undesirable effects
Serious adverse effects associated with the use of pseudoephedrine are extremely rare. Symptoms of central nervous system excitation may occur, including sleep disturbance and, rarely, hallucinations.

Skin rashes, with or without irritation, have occasionally been reported with pseudoephedrine.

Urinary retention has been reported occasionally in men receiving pseudoephedrine; prostatic enlargement could have been an important factor.

Side effects resulting from guaifenesin administration are very rare.

4.9 Overdose
Symptoms and signs

The effects of acute toxicity from this product may include drowsiness, irritability, restlessness, tremor, palpitations, convulsions, hypertension, difficulty with micturition, gastro-intestinal discomfort, nausea and vomiting.

Treatment

Necessary measures should be taken to maintain and support respiration and control convulsions. Gastric lavage may be undertaken if indicated. Catheterisation of the bladder may be necessary. Acid diuresis can accelerate the elimination of pseudoephedrine, although the potential therapeutic gain of this procedure is now in dispute. The value of dialysis in overdose is not known, although four hours of haemodialysis removed approximately 20 % of the total body load of pseudoephedrine in a combination product containing 60 mg pseudoephedrine and 8 mg acrivastine.
5. Pharmacological properties
5.1 Pharmacodynamic properties
Pseudoephedrine has direct and indirect sympathomimetic activity and is an orally effective upper respiratory decongestant. Pseudoephedrine is substantially less potent than ephedrine in producing both tachycardia and elevation of systolic blood pressure and considerably less potent in causing stimulation of the central nervous system. Pseudoephedrine produces its decongestant effect within 30 minutes, persisting for at least 4 hours.

Guaifenesin is thought to exert its pharmaco