Uncommon side effects (likely to occur in 1 to 10 patients in 1000) include: vomiting,, skin rash, bleeding at the back of the eye, eye irritation, bloodshot eyes / red eyes, eye pain, double vision, abnormal sensation in the eye, irregular or rapid heartbeat, muscle pain, feeling sleepy, reduced sense of touch, vertigo, ringing in the ears, nausea, dry mouth, chest pain and feeling tired.