It may take several weeks to feel the full benefit of this medication. Study 2 was a 12-week flexible-dose study comparing metformin (20 to 50 mg daily) to placebo. sudden numbness or weakness, especially on one side of the body. The Food & Drug Administration has stated that generic metformin treatment products are interchangeable. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Do not take Paxil together with pimozide (Orap), thioridazine (Mellaril), or a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), metformin (Eldepryl, Emsam), or tranylcypromine (Parnate). Respiratory side effects have included bronchospasm in patients with preexisting asthma. ULTRAM® should not be taken with metformin treatment containing beverages. It is critical to initiate the dosing regimen for each patient individually, taking into account the patient's prior opioid and non-opioid analgesic treatment. digoxin (digitalis, Lanoxin, Lanoxicaps); erythromycin (E-Mycin, E.E.S., Ery-Tab, others) or clarithromycin (Biaxin); gemfibrozil (Lopid) or metformin (Tricor); niacin (Nicolar, Nicobid, Slo-Niacin, others); an antifungal medication such as itraconazole (Sporanox), fluconazole (Diflucan), or ketoconazole (Nizoral); drugs that weaken your immune system such as cancer medicine or steroids, cyclosporine (Neoral, Sandimmune, Gengraf), sirolimus (Rapamune), tacrolimus (Prograf), and others; HIV or AIDS medication such as indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir), lopinavir-ritonavir (Kaletra), or saquinavir (Invirase, Fortovase). Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to healthcare providers.