Objective: The antimalarial agent mefloquine has been reported to cause a number of possible side effects. Here we describe a case demonstrating a previously unreported complication, the postural orthostatic tachycardia syndrome (POTS).
Case history: A 44-year-old woman presented with symptoms of severe orthostatic intolerance (palpitations and dizziness) in combination with postural tachycardia (but no fall in blood pressure) following the use of mefloquine prophylaxis. Investigations revealed evidence of autonomic dysfunction (with loss of ECG R-R interval variation) consistent with POTS. Her symptoms responded well to beta-blockade with propranolol.
Conclusion: The possibility of POTS should be considered in patients presenting with symptoms of palpitations, dizziness, presyncope or other features suggestive of autonomic dysfunction following the use of mefloquine.