Indications
Chlorobutanol is used mainly as a preservative in medicines such as eye drops, nasal sprays and drops, ear drops, inhalation products and some injections, to stop the growth of bacteria and fungi after the container is opened. It also has mild sedative and local numbing (anaesthetic) properties, and in some products it is included to soothe irritation. It is an inactive or supporting ingredient rather than a main treatment.
How It Works
Chlorobutanol is a chlorinated alcohol. At the low concentrations used in medicines (usually up to about 0.5%) it damages the outer membranes of bacteria and fungi, keeping the product free from contamination. Its mild numbing effect comes from a light action on nerve endings.
Dosage and Administration
Chlorobutanol is not used on its own as a medicine. Use the product that contains it exactly as directed on the label or by your doctor. Injections that contain it are given by a doctor or nurse.
Interactions
No important interactions are expected at the small amounts used as a preservative. In larger amounts it can add to the drowsiness caused by alcohol, sedatives or sleeping medicines.
Contraindications
- Allergy or sensitivity to Chlorobutanol or any other ingredient of the product
Side Effects
Most people have no problems. Possible effects include mild stinging, burning or irritation where the product is applied (for example in the eye or nose) and, rarely, allergic reactions. With long-term frequent use of eye drops, preservatives can irritate the surface of the eye. Large amounts swallowed or injected can cause drowsiness.
Get urgent medical help for swelling of the face, eyes or throat, difficulty breathing, severe eye pain or sudden change in vision, or marked drowsiness after a product is swallowed.
Pregnancy and Lactation
The small amounts used as a preservative are not expected to cause harm. Follow the advice for the main medicine in the product, and ask your doctor or pharmacist if unsure.
Precautions and Warnings
Remove soft contact lenses before using eye drops that contain preservatives and wait about 15 minutes before putting them back. Do not touch the tip of the dropper to the eye or nose. Discard the product as directed after opening.
Overdose
Swallowing a large amount, especially by a child, may cause drowsiness, dizziness or slowed breathing. Contact a doctor or poison service straight away.
Therapeutic Class
Preservative (antimicrobial) with mild sedative and local anaesthetic properties; pharmaceutical excipient.
Storage
Store below 30°C in a dry place, away from light, tightly closed and out of the reach of children. Chlorobutanol can evaporate, so keep the container closed.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.