celecoxib

Mechanism

NSAIDs reduce renal blood flow via prostaglandin blockade. The ACE-I (enalapril) dilates glomerular efferent arterioles. 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

For prolonged celecoxib therapy, check creatinine 2–4 weeks after start, then every 3 months. In older patients and chronic kidney disease, paracetamol is preferable.

Mechanism

Contrast (iopromide) and an NSAID (celecoxib) are both nephrotoxic. NSAID-induced reduction in renal blood flow amplifies contrast-induced nephropathy risk, especially in chronic kidney disease.

Symptoms

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

Management

Stop celecoxib 48 hours before planned contrast and resume 48 hours after with stable renal function. Provide contrast nephroprotection with adequate saline hydration.

Mechanism

Dual NSAID therapy – additive GI bleeding, nephrotoxicity, and cardiovascular event risks. Ketorolac itself is limited to 5 days of use.

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

The combination is not prescribed. One NSAID at a time. For enhanced analgesia, add paracetamol or a short opioid course, not a second NSAID.

Mechanism

NSAIDs (including selective COX-2 inhibitors like celecoxib) reduce renal lithium clearance. Lithium plasma levels rise.

Symptoms

Tremor, muscle twitching, nausea, diarrhoea, confusion, ataxia. Symptoms emerge when serum lithium exceeds 1.2 mmol/L.

Management

For prolonged celecoxib therapy, reduce lithium by 25%; check level at 1 week and then monthly. Alternative analgesic without lithium effect: paracetamol.

Mechanism

Similar to enalapril + celecoxib. NSAIDs reduce renal blood flow; the ARB (losartan) 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

For prolonged celecoxib therapy, check creatinine 2–4 weeks after start, then every 3 months. In older patients and chronic kidney disease, paracetamol is preferable.

Mechanism

NSAIDs reduce renal methotrexate clearance (both selective and non-selective COX inhibitors).

Symptoms

Mouth ulcers (mucositis), nausea, diarrhoea, hair loss. Blood counts fall: leukocytes, platelets, erythrocytes. Severe cases: fatal pancytopenia, nephrotoxicity.

Management

At oncologic methotrexate doses, the combination is not prescribed. At low rheumatologic doses, celecoxib is acceptable with full blood count and creatinine monitoring every 1–3 months.

Mechanism

Celecoxib (a selective COX-2 inhibitor) reduces renal blood flow via prostaglandin suppression. Tacrolimus is nephrotoxic in its own right. Additive acute kidney injury risk, especially with borderline renal function.

Symptoms

Reduced urine output, rising creatinine, potassium accumulation. In kidney transplant patients: accelerated graft function decline.

Management

Avoid chronic celecoxib on tacrolimus. For analgesia post-transplant, use paracetamol (up to 2 g/day) or a short opioid course. For neuropathic pain, gabapentin or pregabalin. Check creatinine monthly.

Mechanism

Celecoxib is metabolised by CYP2C9 – the same route as S-warfarin (the more active form). Enzyme competition raises INR. Celecoxib also moderately injures the gastric mucosa.

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

The combination is acceptable when chronic NSAID therapy is needed. Check INR at 1 and 2 weeks after starting celecoxib, then monthly. PPI cover with pantoprazole is mandatory.