Interactions and Contraindications

Question 1

Below is a list of some OTC medicines that should be avoided or used with caution in people with asthma:

Answer 1

• Aspirin and other NSAIDs (such as ibuprofen) can precipitate an asthmatic attack in a small number of people with asthma. The attack may be severe and sometimes life-threatening. Patients with nasal polyps are at greater risk.
• Cough suppressants such as codeine, pholcodine and dextromethorphan.
• Head lice preparations containing alcohol may trigger an asthmatic attack.
• Patients prescribed theophylline or aminophylline should avoid taking - OTC products containing theophylline such as Do-Do Chesteze which may cause theophylline toxicity (theophylline has a narrow therapeutic range).

Question 2

Below are some examples of medicines that can be found in OTC products that should be avoided or used with caution in patients with prostate enlargement, also known as benign prostatic hyperplasia (BPH), as they may precipitate urinary retention.

Answer 2

• Antihistamines: Chlorphenamine: Promethazine, Cinnarizine, Meclozine, Triprolidine,
  Diphenhydramine, Buclizine, Doxylamine
• Antimuscarinics: Hyoscine butylbromide, Hyoscine hydrobromide
• Decongestants: Phenylephrine, Pseudoephedrine, Ephedrine
• Phenothiazine: Prochlorperazine maleate

Question 3

Here is a list of drugs that should be avoided or used with caution in people with angle-closure glaucoma.

Answer 3

• Antimuscarinics e.g.
  Darifenacin
  Fesoterodine
  Flavoxate
  Oxybutynin
  Tolterodine
  Ipratropium
  Tiotropium
  Glycopyrronium bromide
  Umeclidinium
  Aclidinium
  Hyoscine
  Dicycloverine
  Atropine
  Procyclidine
  Orphenadrine
  Propantheline
• Antihistamines e.g.
  Cyclizine
  Chlorphenamine
  Hydroxyzine
  Pizotifen
  Promethazine
• Tricyclic antidepressants e.g.
  Amitriptyline
  Doxepin
  Dosulepin
  Clomipramine
• Selective serotonin re-uptake inhibitors (SSRIs) e.g.
  Citalopram
  Sertraline
  Fluoxetine
• Antipsychotic drugs e.g.
  Clozapine
  Quetiapine
• Tetracyclic antidepressants
  Mirtazepine
  Mianserin
• Antiepileptics
  Carbamazepine
  Topiramate
• Sympathomimetics e.g
  Pseudoephedrine
  Phenylephrine
  Xylometazoline
• Centrally acting sympathomimetics e.g.
  Atomoxetine
  Methylphenidate

Question 4

In addition to the above, here are some OTC medicines listed below that should be avoided or used with caution in people with angle-closure glaucoma.

Answer 4

• Antihistamines
  Chlorphenamine (e.g. Piriton)
  Diphenhydramine (e.g. Benylin Chesty Coughs [Original])
  Promethazine hydrochloride (e.g. Sominex)
  Promethazine teoclate (e.g. Avomine)
  Triprolidine (e.g. Multi-Action Actifed Dry Coughs)
  Buclizine (e.g. Migraleve Pink)
  Antazoline (e.g. Otrivine Antistin Eye Drops)
• Decongestants
  Pseudoephedrine (e.g. Sudafed Decongestant)
  Phenylephrine (e.g. Sudafed Sinus Max Strength)
• Phenothiazines
  Prochlorperazine (e.g. Buccastem M)
• Anticholinergics
  Hyoscine hydrobromide (e.g. Kwells)
  Hyoscine butylbromide (e.g. Buscopan IBS Relief)
• Corticosteroids
  Beclometasone (e.g. Beconase Hayfever Nasal Spray)
  Fluticasone (e.g. Pirinase Hayfever Nasal Spray)
  Triamcinolone (e.g. Nasacort Allergy Nasal Spray)