Monday, October 5, 2009

Drugs to be Taken on Empty Stomach

Drugs to be taken on empty stomach should be taken either 1 hour before or 2 hours after meals. However, in the hospital scenario, in order not to confuse patients, we usually cancel the 'selepas' for the label to read 'sebelum makan'.

Here are some common examples of drugs to be taken on empty stomach and the reasons for doing so.

where the oral bioavailability of the drug is reduced by more than 20% by food
  • 6-mercaptopurine

  • alendronate

  • atenolol

  • azithromycin

  • captopril

  • ferrous fumarate

  • indinavir (heavy/large meals only)

  • d-penicillamine (take with food if GI upset)

  • dicloxacillin

  • didanosine

  • erythromycin base (erythromycin estolate, erythromycin stearate: take with food as drugs may cause a signicicant incidence of gastric side effects)

  • flucloxacillin

  • gemfibrozil

  • isoniazide

  • perindopril

  • rifampicin

  • tacrine

  • tetracycline

  • lansoprazole

As gastric acid secretion is maximally stimulated by food ingestion, maximal efficacy of proton pump inhibitors (e.g. omeprazole, pantoprazole, lansoprazole) should be achieved when they are taken before a meal.

where the presence of food reduces the effectiveness of the preparation but is unrelated to absorption
  • bismuth subcitrate

  • sucralfate (theoretical)

where the rate of absorption of the drug is significantly reduced by food and clinical effect is related to rapid absorption
  • bumetanide

  1. The Dispensing Guide 2001, The Pharmaceutical Society of New Zealand



  1. Once-daily dosing in the morning is more effective than dosing in the evening for all proton pump inhibitors with respect to the suppression of intragastric acidity and daytime gastric acid secretion in particular, which may result from a better bio-availability being achieved with the morning dose. When higher doses are needed, these drugs must be given twice daily to achieve the optimal suppression of 24 hour intragastric acidity.

    Pharmacological and pharmacodynamic essentials of H2-receptor antagonists and proton pump inhibitors for the practising physician
    Best Practice & Research Clinical Gastroenterology, Volume 15, Issue 3, Pages 355-370
    J.Huang, R.Hunt

  3. another drug to add in the list: Deferasirox (Exjade®)

    administration: disperse tablets in water, orange or apple juice. Stir to form suspension and drink entire contents. Administer at same time each day on empty stomache, 30 min before food. Do not use with aluminium containing antacid.