Pharmacokinetic interactions occur when one drug affects the absorption, distribution, metabolism, or excretion of another drug.

Vitamin K is a known antagonist of warfarin, which can reduce its anticoagulant effect.

Nausea is the most common adverse effect of methotrexate, which is a chemotherapy drug.

Amiodarone, quinidine, and sotalol are all known to cause QT prolongation, which can increase the risk of torsades de pointes, a potentially fatal heart rhythm disorder.

Cardiac arrhythmias are the most common adverse effect of digoxin, which is a heart medication.

Diuretics, NSAIDs, and ACE inhibitors can all interact with lithium, increasing the risk of lithium toxicity.

Dizziness, ataxia, and nystagmus are all common adverse effects of phenytoin, which is an anticonvulsant medication.

Acetaminophen, ibuprofen, and aspirin can all interact with alcohol, increasing the risk of liver damage.

Nausea is the most common adverse effect of chemotherapy, which is a cancer treatment.

Sulfonamides, penicillin, and tetracycline can all cause Stevens-Johnson syndrome, a rare but serious skin condition.

Skin irritation is the most common adverse effect of radiation therapy, which is a cancer treatment.

Statins, calcium channel blockers, and beta-blockers can all interact with grapefruit juice, increasing the risk of adverse effects.

Skin rash is the most common adverse effect of immunotherapy, which is a cancer treatment.

Acetaminophen is the only drug listed that can cause hepatotoxicity, which is a liver condition.

Nausea, vomiting, and diarrhea are all common adverse effects of antibiotics.