Maxi-Analgesic Dose Response Study

Inclusion Criteria:

1. Provide written informed consent before initiation of any study-related procedures.
2. Males and females aged at least 16 years and not more than 40 years old on the day of consent.
3. Undergoing oral surgery for the extraction of 2 impacted 3rd molar teeth, one of which must be mandibular and require bone removal.
4. Experiencing moderate to severe post-operative pain, as defined by a 4 point categorical pain intensity rating scale with 0 = no pain; 1 = mild pain; 2 = moderate pain and 3 = severe pain(at rest) within 6 hours after completion of surgery.
5. Baseline VAS pain intensity score of > 50mm on a 100mm VAS scale with 0 = no pain and 100 = worst pain imaginable.

Exclusion Criteria:

Study contra-indications:

1. Has taken any NSAID or acetaminophen within 12 hours prior to the start of surgery other than aspirin ≤ 150mg/day.
2. Subjects who have received any anesthetics from midnight the night prior to surgery, except for lidocaine with epinephrine, nitrous oxide, diazepam (Valium®), methohexital (Brevital®).
3. Known to be pregnant or possibly pregnant.
4. Women of childbearing potential who are unwilling to take adequate contraceptive precautions, i.e., a hormonal contraceptive, an intrauterine device, double-barrier method, or abstinence (should the subject become sexually active, she must agree to use a double-barrier method of contraception). A woman of childbearing potential is defined as any female who is less than 2 years post-menopausal or has not undergone a partial or total hysterectomy or surgical sterilization, e.g., bilateral tubal ligation, bilateral oophorectomy.
5. Suffering from a neurological disorder relating to pain perception or any acute or chronic condition that, in the opinion of the investigator, makes the subject unsuitable from an efficacy or safety perspective.
6. In the opinion of the investigator, unable to understand the visual analogue pain score or comply with the protocol requirements.
7. Currently or in last 30 days, has been in a clinical trial involving another study drug.
8. Currently treated with an ACE inhibitor, warfarin, steroid (other than nasal steroids or topical steroids with the approval of the investigator), cyclosporin, tacrolimus or methotrexate, or any other medication felt by the investigator to interfere with safety or efficacy evaluations.

9. Participant weight < 50kg.Suffering from any other diseases or condition which, in the opinion of the investigator, means that it would not be in the participant's best interests to participate in this study.

   NSAID and/or acetaminophen contra-indications:

10. Hypersensitivity to aspirin or other NSAID.
11. Hypersensitivity to acetaminophen.
12. Severe known hemopoietic, renal or hepatic disease, or immunosuppressed.
13. History of gastric ulceration or other GI disorders that, in the opinion of the investigator make the subject unsuitable (e.g., frequent treatment of GERD, inflammatory bowel disease, etc.).
14. History of severe asthma defined as asthma requiring frequent or ongoing treatment to control symptoms. Exercise-induced asthma or mild asthma not requiring ongoing treatment may not be exclusionary at the discretion of the investigator.