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Contraindications and cautions

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Contraindications and cautions

Amoxicillin

Amoxicillin, like other penicillins, can result in hypersensitivity reactions, including rashes and anaphylaxis, and can cause antibiotic-associated colitis, which may be fatal. Do not give amoxicillin to patients with a history of anaphylaxis, urticaria or rash immediately after penicillin administration as these individuals are at risk of immediate hypersensitivity. Amoxicillin should also be avoided in patients with milder forms of penicillin allergy, such as non-immediate generalised rash, but does not need to be avoided in patients who only report gastrointestinal side effects following penicillin administration. Amoxicillin potentially alters the anticoagulant effect of warfarin and therefore the INR of a patient taking warfarin should be monitored.

Azithromycin

Azithromycin can cause abdominal discomfort, diarrhoea, nausea and vomiting in some patients. Use azithromycin with caution in patients who are predisposed to QT interval prolongation including electrolyte disturbances and those with hepatic impairment or renal impairment.

Cefazolin/ceftriaxone

Cefazolin and ceftriaxone should not be used in patients with a history of immediate or severe hypersensitivity to penicillins, but can usually be safely administered to patients with a history of mild penicillin allergy.

Clarithromycin

Clarithromycin should be used with caution in patients who are predisposed to QT interval prolongation including electrolyte disturbances and those with hepatic impairment or renal impairment. Do not prescribe clarithromycin in pregnancy. Do not prescribe clarithromycin to patients taking warfarin or statins. Clarithromycin is also contraindicated in any patient with a heart transplant taking calcineurin inhibitors (e.g. tacrolimus, ciclosporin).

The SDCEP Drug Prescribing for Dentistry guidance provides information on prescribing in dental practice.

For more-detailed information on contraindications, cautions and side-effects, refer to the BNF and BNFC (available at https://bnf.nice.org.uk/).