Antidotes: benefits and risks.

The ability of naloxone and flumazenil to reverse serious toxicity due to their respective agonists is well known. Their adverse effects are minor and few but flumazenil administration may unmask seizures in poisoning with combinations of benzodiazepines and tricyclic antidepressants. The desferrioxamine challenge test is frequently falsely negative and should be abandoned. In addition to being cytoprotective, N-acetylcysteine has potent vasodilator and positive inotropic actions which may be partly responsible for its beneficial effect in late-presentation paracetamol overdosage with hepatic damage and failure.