Critical Drug - Drug Interactions

What happens when warfarin is combined with aspirin or NSAIDs?

Major increased risk of bleeding

What is the interaction between warfarin and fluconazole or amiodarone?

↑ INR → increased bleeding risk.

Why is MAOIs + SSRIs/SNRIs dangerous?

Can cause serotonin syndrome (life-threatening).

What happens when statins are combined with gemfibrozil?

Increased risk of rhabdomyolysis.

Why is ACE inhibitors + ARBs or aliskiren dangerous?

Severe hyperkalemia and kidney failure risk.

What is the interaction between digoxin and amiodarone?

Increased digoxin levels → toxicity.

Why is methotrexate + NSAIDs dangerous?

Methotrexate toxicity due to reduced clearance.

What happens when sildenafil (Viagra) is taken with nitrates?

Severe hypotension (dangerous blood pressure drop).

Why does omeprazole affect clopidogrel?

It reduces clopidogrel effectiveness.

What happens when fluoroquinolones are taken with antacids?

Decreased antibiotic absorption → reduced effect.

Why should tetracyclines not be taken with dairy or calcium?

Calcium binds drug → decreased absorption.

Why is opioids + benzodiazepines a high-risk combo?

Severe respiratory depression (black box warning).