Methylcobalamin: pulmonary edema & CHF early in treatment, peripheral vascular thrombosis; polycythemia vera; mild transient diarrhea; itching, transitory exanthema; feeling of swelling of entire body. Pregabalin: dizziness, somnolence, dry mouth, edema, blurred vision, wt gain, "thinking abnormal" (primarily difficulty w/ concentration & attention); asthenia, ataxia, abnormal gait, paresthesias, diplopia, blurred vision, visual field defect, nystagmus, nausea, tremor, vertigo, headache, nervousness, confusion & edema. Abdominal pain, allergic reaction, fever, flu syndrome, accidental injury; ST depressed, ventricular fibrillation; gastroenteritis, nausea, diarrhea, flatulence, dry mouth, increased appetite, constipation; ecchymosis; wt gain, peripheral edema; arthralgia, leg cramps; myalgia, myasthenia; headache, nervousness, dizziness, vertigo, somnolence, ataxia, tremor, thinking abnormal, amnesia, speech disorder, incoordination, abnormal gait, twitching, confusion, anxiety, depersonalization, hypertonia, hypesthesia, libido decreased, nystagmus, paresthesia, stupor, twitching, euphoria; bronchitis, dyspnea; pruritus, face swelling, Stevens-Johnson syndrome; conjunctivitis, diplopia, blurred vision, abnormal vision, otitis media, tinnitus; anorgasmia, impotence, urinary frequency, urinary incontinence.