Efficacy and Safety Clinical Trial of the Combination of Acetylsalicylic Acid, Sodium Bicarbonate and Citric Acid, Produced by Geolab Pharmaceutical Industries Ltd., Compared to Acetylsalicylic Acid (Aspirin ® - Bayer) in Patients With Episodic Tension-type Headache.

Efficacy and Safety Clinical Trial of the Combination of Acetylsalicylic Acid, Sodium Bicarbonate and Citric Acid, Produced by Geolab Pharmaceutical Industries Ltd., Compared to Acetylsalicylic Acid (Aspirin ® - Bayer) in Patients With Episodic Tension-type Headache.

This study aims is to evaluate, two hours after a single administration, the rate of sustained response produced by the association Geolab consisting of acetylsalicylic acid, sodium bicarbonate and anhydrous citric acid - oral powder, with the active comparator acetylsalicylic acid (Aspirin ® -- Bayer) - a simple tablet for the treatment of acute pain in patients with mild to moderate CTTE, using for both the visual analog scale pain - VAS.

The secondary objectives of the study are to evaluate: Modification of gastric pH after administration of drugs by measuring with gastroesophageal pH Monitor, comparing the results between the groups; The incidence of administration of rescue medications, through the accounts of patients and researchers, comparing the results between the groups; The percentage of improvement in time 30, 60, 90 and 120 minutes after administration, using the visual analog scale (VAS), comparing the results between the groups; Evaluate the gastric symptoms before and after treatment by clinical investigation of patients, comparing the results between the groups; Evaluate the change in associated symptoms (photophobia, phonophobia, nausea, vomiting), using 4-point scale (0 - absent 1 - mild 2 - moderate 3 - severe), comparing the results between the groups; Assess the quantitative and qualitative parameters related to adverse reactions, comparing the results between the groups.

The primary efficacy endpoint is the rate of sustained response (percentage of subjects who have no pain) two hours after the drug administration.

• Reduction of associated symptoms (photophobia, phonophobia, nausea, vomiting); • Symptoms stomach before and after treatment • Change in gastric pH after administration; • Incidence of administration of rescue medications; • Change in pain

Inclusion Criteria: Agreed to participate in the study expressed by signing the two copies of the informed consent and informed consent (IC) after approved by the IRB; Minimum age of 18 years; Clinical history of TTH, according to the criteria of the International Classification of Headache of the International Headache Society, in face of crisis. Exclusion Criteria: Headache, migraine Chronic Tension-Type Headache (CTTH) Altered mental status Vital signs changed established or suspected pregnancy and lactation History of allergy to components of study drugs Current treatment with methotrexate Current treatment with Antinauseants Current treatment with anticoagulants such as heparin or coumarin-derivative gastric or duodenal disorders, chronic or recurrent active Liver and kidney disease severe Use of medications that have drug interactions with AAS