Lower UTI Drugs for Men Flashcards
Do not prescribe amoxicillin in people with
A true penicillin allergy — allergic reactions to penicillins occur in 1–10% of exposed individuals. Anaphylactic reactions occur in fewer than 0.05% of treated patients.
Gastrointestinal adverse effects alone (for example nausea, vomiting, or diarrhoea) do not constitute an allergy to penicillin. See the CKS topic on Angio-oedema and anaphylaxis for more information
Prescribe amoxicillin with caution to people with
Hypersensitivity to cephalosporins. Renal impairment — reduce the dose of amoxicillin in severe renal impairment. Glandular fever (infective mononucleosis) — these people are especially susceptible to amoxicillin-induced skin rashes.
Adverse effects of amoxicillin
Gastrointestinal — nausea and diarrhoea (common), vomiting (uncommon).
Very rarely: antibiotic associated colitis.
Skin — skin rash (common), urticaria and pruritus (uncommon).
Very rarely: erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, bullous and exfoliative dermatitis and acute generalised exanthematous pustulosis.
Other very rare adverse effects include:
Hepatitis, cholestatic jaundice.
Hyperkinesia, dizziness, convulsions.
Interstitial nephritis.
Leukopenia, thrombocytopenia, haemolytic anaemia.
Severe allergic reactions.
Drug interactions of amoxicillin
Allopurinol — increased risk of rash when allopurinol is given with amoxicillin.
Methotrexate — amoxicillin may reduce methotrexate clearance, causing an increased risk of toxicity.
Monitor methotrexate levels more closely. One recommendation is to carry out twice weekly platelet and white cell counts for 2 weeks initially, with the measurement of methotrexate levels if toxicity is suspected.
Oral anticoagulants (warfarin, phenindione) — INR may be increased. Monitor the international normalized ratio (INR) closely during concomitant use. Dosage adjustments may be necessary.
Do not prescribe trimethoprim in people with
Severe hepatic insufficiency, or severe renal insufficiency.
Blood dyscrasias
Prescribe trimethoprim with caution in people:
With impaired renal function.
With hyperkalaemia, or taking medication that is known to cause hyperkalaemia.
With acute porphyria.
Predisposed to folate deficiency — because of the potential anti-folate effect of trimethoprim, there is a risk of further exacerbating folate deficiency in people who are folate deficient, or who are predisposed to folate deficiency (for example elderly people), or who are taking folate antagonists.
Adverse effects of trimethoprim
Blood disorders — leukopenia, megaloblastic anaemia, thrombocytopenia, agranulocytosis, methaemoglobinaemia.
Gastrointestinal — nausea, diarrhoea, vomiting (common).
Nervous system — aseptic meningitis (frequency unknown).
Skin — pruritus, and skin rashes (common).
Rarely: Photosensitivity, exfoliative dermatitis, fixed drug eruption, erythema multiforme, erythema nodusum, Stevens-Johnson Syndrome, toxic epidermal necrolysis, bullous dermatitis, purpura, angioedema.
Other adverse effects include:
Anaphylaxis.
Hyperkalaemia (particularly in the elderly and in HIV patients)
Liver enzyme disturbances, cholestatic jaundice.
Myalgia.
Raised serum creatinine.
Drug interactions of trimethoprim
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin-II receptor antagonists AIIRAs — there may be an increased risk of hyperkalaemia with the concurrent use of these drugs and trimethoprim. Monitor potassium concentrations.
Azathioprine and mercaptopurine — increased risk of haematological toxicity in people who have had a renal transplant. However, the combination is commonly used in practice. Monitor the full blood count routinely.
Ciclosporin — serum creatinine levels may be increased. Possible increased risk of nephrotoxicity. Monitor renal function closely.
Coumarins (warfarin) — the anticoagulant effect of coumarins may be potentiated. Monitor international normalised ratio (INR) and adjust dose accordingly.
Digoxin — digoxin levels may be increased in the elderly if taken with trimethoprim. Monitor for digoxin adverse effects, and adjust dose accordingly.
Diuretics — hyperkalaemia may be exacerbated by concomitant administration of diuretics, particularly potassium sparing diuretics and/or thiazide diuretics and eplerenone.
Methotrexate (a folate antagonist) — there is an increased risk of haematologic adverse effects. Several cases of bone marrow suppression have been reported (some fatal). Full blood count should be monitored routinely.
Phenytoin — phenytoin levels may be increased if taken with trimethoprim. Monitor phenytoin levels and adjust dose accordingly.
Do not prescribe nitrofurantoin in infants aged less than 3 months, or people with:
Acute porphyria.
Renal impairment — estimated glomerular filtration rate (eGFR) less than 45 mL/minute/1.73 m2.
A short course of up to 7 days may be used if the eGFR is 30–44 mL/minute/1.73 m2 and a urinary tract infection has suspected or proven multi-drug resistance, when the benefits of nitrofurantoin are considered to outweigh the risks of adverse effects.
Glucose-6-phosphate dehydrogenase deficiency.
Prescribe nitrofurantoin with caution in people with
Peripheral neuropathy or susceptibility to peripheral neuropathy — treatment should be stopped at the first signs of neural involvement (paraesthesiae).
Anaemia, diabetes mellitus, electrolyte imbalance, debilitating conditions, and vitamin B (particularly folate).
Adverse effects of NF
Blood disorders — agranulocytosis, leukopenia, granulocytopenia, haemolytic anaemia, thrombocytopenia, megaloblastic anaemia, glucose-6-phosphate dehydrogenase deficiency anaemia, and eosinophilia (frequency unknown).
Rarely: aplastic anaemia.
Gastrointestinal — nausea, anorexia, vomiting, abdominal pain, and diarrhoea (frequency unknown).
Hepatobiliary disorders — chronic hepatitis, cholestatic jaundice (frequency unknown).
Respiratory — acute pulmonary reactions may occur within the first week of treatment, and are manifested by: fever, chills, cough, chest pain, dyspnoea, and eosinophilia. Reversible on stopping treatment.
Rarely: chronic pulmonary reactions occur in people who have received continuous therapy for six months or longer. It is more common in the elderly.
Nervous system — peripheral neuropathy, nystagmus, vertigo, dizziness, asthenia, headache and drowsiness (frequency unknown).
Psychiatric disorders — depression, euphoria, confusion, psychotic reactions (frequency unknown).
Skin — angioneurotic oedema, maculopapular, erythematous or eczematous eruptions, urticaria, rash, pruritus, lupus-like syndrome, exfoliative dermatitis and erythema multiforme (including Stevens-Johnson Syndrome).
Drug interactions of NF
Alkalinizing agents (such as potassium citrate) — the antibacterial activity of nitrofurantoin is reduced when the pH of the urine is increased. It may be prudent to avoid in people taking nitrofurantoin, however there is no evidence that this possible interaction presents a problem in practice. Magnesium trisilicate — absorption of nitrofurantoin may be reduced
Do not prescribe pivmecillinam in people with
A true penicillin allergy — allergic reactions to penicillins occur in 1–10% of exposed individuals. Anaphylactic reactions occur in fewer than 0.05% of treated patients.
Gastrointestinal adverse effects alone (for example nausea, vomiting, or diarrhoea) do not constitute an allergy to penicillin. See the CKS topic on Angio-oedema and anaphylaxis for more information.
Acute porphyrias.
Carnitine deficiency.
Gastrointestinal obstruction.
Oesophageal strictures
Prescribe pivmecillinam with caution to people
With hypersensitivity to cephalosporins.
Taking valproic acid, or valproate concurrently, or any other medication liberating pivalic due to increased risk of carnitine depletion
Adverse effects of pivmecillinam
Common adverse effects include: Diarrhoea. Nausea. Vulvovaginal fungal infection. Uncommon adverse effects include: Dizziness. Fatigue. Gastrointestinal discomfort/disorders. Headache. Oral ulceration. Skin reactions. Thrombocytopenia. Vertigo.
