Sir, it has recently come to our attention that the capsules used in certain antibiotics (and also analgesics in capsule form) contain gelatine of animal origin. Details of capsule constituents is given in the patient information leaflet supplied with the medicine, but generally states simply 'gelatin'. This gelatine is generally derived from mixed porcine/bovine sources, and as such may be unacceptable to some patients for religious or ethical reasons. Whilst some of these patients would be happy to take these antibiotics as a necessary medical treatment, others may choose not to do so – especially if an alternative is available. Note: this consideration is not present in tablet form antibiotics eg metronidazole, co-amoxiclav.

At least one brand of amoxicillin (Accord) supplies capsules of bovine-only, Halal-certified origin, but obtaining these specific antibiotics may be difficult or impossible. Obviously this still does not solve the problem for patients wishing to avoid products of bovine origin. NEWT guidelines (for administration of medication to patients with enteral feeding tubes or swallowing difficulties)1 do not specify whether amoxicillin capsules can be opened and their contents dispersed, so this is perhaps inadvisable.

A feasible alternative to amoxicillin capsules is to prescribe suspension form. Amoxicillin is available in up to 250 mg/5 ml suspension: a 100 ml bottle costs £1.33, compared to £1.30 for 21 × 250 mg capsules, or £1.57 for 21 × 500 mg capsules.2

Clindamycin capsules can be opened, but the NEWT guidelines suggest that the contents be dispersed in 'grape juice or maple syrup' due to the bad taste! Whether or not the patient would be happy to ingest contents which have been in contact with the gelatine-containing capsule should be discussed with them prior to prescription in these instances. Clindamycin is available in suspension in unlicensed form, so clinicians would likely need to discuss with the pharmacist whether dispensing this is possible. Clindamycin is therefore unlikely to be the antibiotic of choice in patients objecting to taking gelatine-based capsules.

As clinicians, we must inform our patients as to any risks of treatment that they may perceive as significant, and for many people, this may well include ingestion of porcine or bovine products. Patients should be fully informed about treatments and their alternatives; together with risks of declining treatment, in order to make an informed decision about their care. Clinicians may need to consider this when prescribing capsule-based medicines to their patients.