Theophylline, Versus Sumatriptan and Gabapentin in The Treatment of Post-Dural Puncture Headache

Inclusion Criteria: * Age from 21 to 50 years. * Both sexes. * American Society of Anesthesiologists (ASA) physical status ≤ II. * Patient's selection for this study will be based on clinical diagnosis suggesting post-dural puncture headache (PDPH) based on the International Headache Society criteria. * Patients with numeric rating scale (NRS) of ≥ 5. Exclusion Criteria: * Pregnant women. * History of; chronic headache, cluster headache, migraine, convulsions, cerebrovascular accident, and previous neurological diseases. * Signs of meningismus. * Dysrhythmia. * Hypertension. * Ischemic heart disease. * Hyperthyroidism. * Peripheral vascular disease (ischemic colitis). * Liver or renal impairment. * Use of selective serotonin reuptake inhibitors. * Use of ergotamine derivatives in the past 24 hours. * Use of monoamine oxidase inhibitors in the last 2 weeks. * Use of any kind of opiates. * Allergy to the study medications and any contraindication of oral intake.