Leyla Hannbeck, head of pharmacy at the National Pharmacy Association, answers three of the 700 questions fielded every day by the NPA’s Pharmacy Services team

What are the symptoms of serotonin syndrome, or serotonin toxicity?

Patients taking more than one serotonergic drug concomitantly may be at increased risk of serotonin syndrome, and close monitoring of symptoms is advised. These drugs may include monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, St John's Wort, tramadol, tricyclic antidepressants, triptans and 5HT3-receptor antagonists. Symptoms of serotonin syndrome can develop within a few minutes or hours after exposure and may include:

• Altered mental status – agitation, confusion, delirium, mania and hallucinations
• Autonomic dysfunction – diarrhoea, fever, shivering, flushing, hypertension or hypotension, tachycardia, vomiting
• Neuromuscular abnormalities – myoclonus (sudden muscle spasms), hyperreflexia, shivering, teeth grinding or tremor.

In severe cases, drowsiness, coagulopathies (clotting disorders), coma, hyperthermia, renal failure, rhabdomyolysis (muscle injury) and seizures may develop.

Can Keppra oral solution 100mg/ml be used in children under four years of age?

Keppra oral solution 100mg/ml be used in children under four years of age, but the appropriate presentation prescribed will depend on the age of the child. There are three presentations of Keppra oral solution 100mg/ml available and it is important that the correct one is prescribed and supplied to ensure that accurate doses are administered:

• For adults, adolescents and children four years of age and over, the 300ml bottle with a 10ml oral syringe (containing up to 1,000mg levetiracetam) graduated every 0.25ml (corresponding to 25mg) should be prescribed.
• For infants and young children from six months to less than four years of age, the 150ml bottle with a 3ml oral syringe (containing up to 300mg levetiracetam) graduated every 0.1ml (corresponding to 10mg) should be prescribed.
• For infants one month to less than six months of age, the 150ml bottle with a 1ml oral syringe (containing up to 100mg levetiracetam) graduated every 0.05ml (corresponding to 5mg) should be prescribed.