Ibuprofen

Mechanism

Ibuprofen reversibly binds platelet COX-1 and blocks aspirin's access to its irreversible acetylation site. Aspirin's antiplatelet effect is lost – cardiovascular event risk.

Symptoms

No symptoms – risk is loss of cardioprotection.

Management

If ibuprofen needed – take 8 hours BEFORE or 30 minutes AFTER aspirin. Alternative in cardiovascular risk – paracetamol.

Mechanism

Apixaban inhibits factor Xa; ibuprofen (NSAID) injures the gastric mucosa and transiently inhibits platelet aggregation. The GI bleeding risk is additive.

Symptoms

Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage. Risk rises in patients over 65 and with prior peptic ulcer disease.

Management

Avoid where possible. If a short ibuprofen course is needed, use the minimum effective dose for no more than 5–7 days under pantoprazole cover. For chronic analgesia, choose paracetamol, a selective COX-2 inhibitor (celecoxib), or topical NSAIDs.

Mechanism

SSRI + NSAID – GI bleeding.

Symptoms

GI bleeding.

Management

PPI or paracetamol.

Mechanism

Ibuprofen (NSAID) suppresses prostaglandin synthesis maintaining glomerular perfusion at lower blood pressure. On enalapril, which dilates efferent arterioles, the combination raises acute kidney injury risk (the 'triple whammy' with a diuretic is more dangerous still).

Symptoms

Reduced urine output, rising creatinine and potassium. Blood pressure rise and oedema. Symptoms appear earlier in older patients and chronic kidney disease.

Management

Avoid chronic ibuprofen on enalapril. If a short course is needed, use the minimum effective dose for 5–7 days with pantoprazole cover. For chronic analgesia: paracetamol, celecoxib, or topical NSAIDs.

Mechanism

SSRI + NSAID – increased GI bleeding risk.

Symptoms

GI bleeding in at-risk patients.

Management

PPI gastroprotection or paracetamol alternative.

Mechanism

Ibuprofen reduces lithium renal clearance by inhibiting prostaglandin synthesis in the proximal tubule. Lithium plasma concentration rises 25–60%, leading to intoxication. Lithium has a narrow therapeutic index (target 0.6–1.0 mmol/L, toxic above 1.5).

Symptoms

Within 5–10 days: nausea, vomiting, diarrhea, tremor, confusion, drowsiness. Severe toxicity: seizures, coma, renal injury, arrhythmia.

Management

In bipolar disorder, paracetamol is the first-line analgesic. If an NSAID is needed, use a short course (up to 5 days); check lithium level 4–7 days after NSAID start and 4–7 days after stop. Reduce lithium by 50% and titrate to level.

Mechanism

NSAIDs reduce renal blood flow via prostaglandin blockade. The ARB (losartan) lowers glomerular pressure. The combination causes acute kidney injury, especially in older patients, chronic kidney disease, and dehydration.

Symptoms

Reduced urine output, rising creatinine and potassium, oedema. Symptoms appear earlier in older patients and in chronic kidney disease.

Management

Avoid prolonged combination. If ibuprofen is needed for a short course, use the minimum effective dose for 5–7 days with pantoprazole cover and creatinine monitoring. For chronic analgesia: paracetamol or celecoxib.

Mechanism

Ibuprofen reduces methotrexate renal elimination by inhibiting proximal tubular secretion. With high-dose methotrexate (oncology, high-dose psoriasis) concentration rises 2–3 fold causing severe myelosuppression and mucositis. With low-dose weekly methotrexate (rheumatoid arthritis 7.5–25 mg/week) risk is lower but not absent.

Symptoms

Within 7–14 days: mouth ulcers, fever, infections, bruising, gum bleeding. CBC: leukopenia, thrombocytopenia; rising creatinine.

Management

With high-dose methotrexate, contraindicated: stop NSAID 48 h before infusion, resume no sooner than 2–3 days after. With low-dose weekly methotrexate, choose paracetamol as first-line analgesic. If an NSAID is needed, check CBC, creatinine and transaminases every 2 weeks for the first 2 months.

Mechanism

Additive gastroesophageal ulcer and bleeding risk. Glucocorticoids reduce GI mucosal repair; NSAIDs block protective prostaglandins.

Symptoms

Black or tarry stools (melena), vomiting blood or coffee-ground material, epigastric pain. Risk multiplies in older patients and with prior peptic ulcer disease.

Management

Avoid prolonged combination. If ibuprofen is needed for a short course on prednisolone, use the minimum effective dose for 5–7 days with mandatory pantoprazole cover. For chronic analgesia: paracetamol or celecoxib.

Mechanism

Additive GI bleeding risk: anticoagulant (rivaroxaban) + ulcerogenic NSAID with antiplatelet effect (ibuprofen).

Symptoms

Black or tarry stools (melena), vomiting blood or coffee-ground material, epigastric pain. Risk multiplies in older patients and with prior peptic ulcer disease.

Management

Avoid prolonged combination. If ibuprofen is needed for a short course, use the minimum effective dose for 5–7 days under pantoprazole cover. For chronic analgesia: paracetamol, celecoxib, or topical NSAIDs.

Mechanism

SSRIs reduce platelet serotonin uptake – impaired aggregation. With NSAIDs (antiplatelet + GI mucosal damage) – significant GI bleeding risk increase.

Symptoms

GI bleeding, especially in patients over 60 with prior peptic ulcer disease.

Management

In high-risk patients – PPI gastroprotection. Alternative analgesic – paracetamol.

Mechanism

Ibuprofen reduces renal blood flow via PGE2 inhibition. Tacrolimus is nephrotoxic in its own right. Additive acute kidney injury risk in transplant patients.

Symptoms

Reduced urine output, rising creatinine and potassium, oedema. Symptoms appear earlier in older patients and in chronic kidney disease.

Management

Avoid prolonged combination. For analgesia post-transplant, use paracetamol (up to 2 g/day) or a short opioid course. For neuropathic pain: gabapentin or pregabalin.

Mechanism

Similar to losartan + ibuprofen. NSAIDs reduce renal blood flow; the ARB (telmisartan) lowers glomerular pressure. The combination causes acute kidney injury.

Symptoms

Reduced urine output, rising creatinine and potassium, oedema. Symptoms appear earlier in older patients and in chronic kidney disease.

Management

Avoid prolonged combination. If ibuprofen is needed for a short course, use the minimum effective dose for 5–7 days with pantoprazole cover and creatinine monitoring. For chronic analgesia: paracetamol or celecoxib.

Mechanism

Ibuprofen and warfarin compete for plasma protein (albumin) binding. The free warfarin fraction rises and its anticoagulant effect intensifies. In parallel, ibuprofen reversibly inhibits platelet aggregation and damages the gastric mucosa – two additional bleeding mechanisms. INR may rise modestly, but gastrointestinal bleeding risk increases independently of INR.

Symptoms

Black or tarry stools (melena), vomiting blood or coffee-ground material, epigastric pain. Less severe presentations: gum bleeding, epistaxis, bruising. Risk multiplies in patients with a history of peptic ulcer disease.

Management

For analgesia in a warfarinised patient, paracetamol is preferred (up to 2 g/day, short courses). If chronic NSAID therapy is needed, switch to a selective COX-2 inhibitor (celecoxib) with proton pump inhibitor cover and frequent INR monitoring. Topical NSAIDs (gels, creams) deliver minimal systemic absorption and are acceptable.