Efficacy of a Single Dose of Aspirin vs. Acetaminophen in Tension Type Headache

Inclusion Criteria: * Healthy, ambulatory, male and female volunteers ages 18-65 years old * History of an onset of tension type headaches before age 50 * Experiencing over the last year ≥ 4 tension type headaches of at least moderate intensity per month and with the majority of headaches lasting greater than three hours, that meet commonly recognized criteria for diagnosis per the International Headache Society * History of response to treatment with over-the-counter (OTC) analgesics * Understand the pain rating scales (as judged by the trial coordinator) * Present with at least moderate headache pain on a 0-10 point numerical rating scale (a score of at least 4 on an 11 point scale ranging from 0 to 10) at the Treatment Visit * Onset of pain within three hours of the Treatment Visit * Confirmation by a physician of acute tension type headache symptoms as described by the International Headache Society diagnostic criteria Exclusion Criteria: * History of hypersensitivity to aspirin, salicylates, other NSAIDs, acetaminophen, and similar pharmacological agents or components of the investigational products, including the placebo * Use of any immediate release analgesic/anti-pyretic within four hours or use of any sustained release or long acting analgesic/anti-pyretic within 12 hours proceeding administration of Investigational Product * Presence of symptoms that are consistent with menstrual headache or migraine headache as described by the International Headache Society diagnostic criteria * History of migraine headaches more than once per month * Relevant concomitant disease such as asthma (exercise induced asthma is permitted), chronic sinusitis or nasal structural abnormalities causing greater than 50 percent obstruction (polyposis nasi, marked septal deviation) that can interfere with the conduct of the trial in the judgment of the Investigator * Current or past history of bleeding disorder(s) * History of gastrointestinal bleeding or perforation, related to previous Nonsteroidal Anti-inflammatory Drugs (NSAID) therapy. Active, or history of recurrent peptic ulcer/hemorrhage (two or more distinct episodes of proven ulceration or bleeding) * Recent head or neck trauma (within 2 weeks) * Current use of blood thinning (anticoagulant), low dose aspirin, or steroid drug