Prophylactic etoricoxib is effective in preventing “first of Ramadan” headache: a placebo-controlled double-blind and randomized trial of prophylactic etoricoxib for ritual fasting headache - Drescher, M J; Wimpfheimer, Z; Abu Khalef, S; Gammaitoni, A; Shehadeh, N; Torgovicky, R (Headache, 2012)