betawinSide effects of Betawin Lc 5 MG · Dry mouth · Headache · Somnolence (excessive sleepiness) · Drowsiness · Constipation · Increased heart rate · Palpitations.Betawin Lc 5 MG Tablet 10 is used to treat various allergic conditions, including hay fever, conjunctivitis, eczema, hives, and reactions to bites and stings.