Maxitrol or Synthomycin – What Is the Difference?

“Maxitrol or Synthomycin?” is a question we hear a lot – sometimes at the pharmacy, sometimes when a tube from a previous treatment is still sitting in the medicine cabinet. Both are small ointments that go in the eye, and both have to do with antibiotics, so it is easy to think one can stand in for the other. In practice they are very different: one contains a steroid and the other does not, and they suit different conditions. This page explains what is in each, why you should not swap one for the other on your own, and when it is worth being examined before applying anything.

In short: what is the difference

• Maxitrol – an ointment (also available as drops) that combines a steroid called dexamethasone with two antibiotics, neomycin and polymyxin B. It calms inflammation and provides antibiotic coverage.
• Synthomycin – an ointment containing a single antibiotic, chloramphenicol, with no steroid. The eye ointment is intended for superficial bacterial infections of the conjunctiva and cornea.
• Both require a prescription, and neither helps with allergy, dryness or viral inflammation.
• The key practical difference is the steroid: it is what makes Maxitrol effective at calming inflammation – and what makes it dangerous when used without an examination.

What is Maxitrol

Maxitrol is intended for short-term treatment of inflammatory eye conditions that respond to a steroid, when the doctor also wants antibiotic coverage – and only after making sure there is no viral or fungal infection. The steroid quickly reduces redness, swelling and discomfort, which is why many people feel relief within a day or two.

But a steroid in the eye has a price when it is given without a diagnosis. It can severely worsen corneal inflammation caused by the herpes virus as well as fungal inflammation, raise eye pressure without any sensation at all, and with prolonged use contribute to the development of cataract. In addition, neomycin – one of the two antibiotics in the ointment – is a well-known cause of local allergy: red, itchy, swollen eyelid skin that appears precisely during treatment. More on how to use it and its side effects in Maxitrol ointment.

What is Synthomycin – and why check what the tube says

The active ingredient in Synthomycin is chloramphenicol, a long-established antibiotic that works against many of the bacteria that cause superficial eye infections. It contains no steroid, so it does not calm non-infectious inflammation, and it does not raise eye pressure the way a steroid can.

One point worth knowing: two different products are marketed in Israel under the Synthomycin name – an eye ointment and a skin ointment at a different concentration. The leaflet of the skin ointment states explicitly that it is not intended for use in the eyes, and that if it gets into the eye it should be rinsed out with water. So before putting an ointment in your eye, check that the package says “eye ointment”. The same applies to chloramphenicol skin ointments bought abroad.

There is a long-standing debate in the medical literature about chloramphenicol: when taken by mouth it is linked to rare damage to the bone marrow, while for eye drops and ointments the risk is considered very low and has not been clearly proven. In practice, the leaflet asks you to tell your doctor if you have had a bone marrow or blood count problem in the past, and to see a doctor if fever, sore throat, paleness or a tendency to bleed appears during or after treatment.

When a doctor chooses each one

An antibiotic alone (such as Synthomycin) is mainly suited to superficial bacterial infection – for example, bacterial conjunctivitis with a pus-like discharge. It is important to know that mild bacterial conjunctivitis often clears up on its own within about a week, and the antibiotic shortens the course and reduces contagion. A red eye with watery discharge, itching or a gritty feeling is usually viral, allergic or dry – and there an antibiotic ointment will not help. On the differences between the types of products, see antibiotic eye drops.

A combination of a steroid and an antibiotic (such as Maxitrol) is reserved for situations in which the doctor wants to calm inflammation and has found on examination that there is no contraindication – for example, an inflammatory flare of the eyelids or the eye surface in selected cases, or as instructed after surgery. It is not a first-line medication for a red eye that has not been examined. Medical reviews advise doctors who are not ophthalmologists to avoid giving steroid drops for a red eye without a slit-lamp examination, precisely because of the risk of worsening herpes.

What about a stye?

Many people look for an ointment when a stye appears – a painful lump at the edge of the eyelid. In most cases the treatment is warm compresses several times a day and keeping the eyelid clean. An antibiotic ointment applied to the eye usually does not reach inside the blocked gland, so its benefit for an internal stye is limited. A steroid is not the first step either. A stye that does not improve, swelling that spreads across the whole eyelid, or fever – all warrant an examination.

Contact lenses

Do not wear contact lenses while using eye ointments. Beyond that: contact lens wearers with a red, painful eye, sensitivity to light or reduced vision should be examined the same day, rather than trying an ointment from home. Lens-related infections are often caused by different bacteria and require diagnosis and tailored treatment – see contact lens keratitis.

How to use them correctly – both ointments

1. Wash your hands.
2. Gently pull down the lower eyelid and place a thin strip of ointment, in the amount stated in the leaflet or prescribed by the doctor, into the pocket that forms, without letting the tip of the tube touch the eye or the lashes.
3. Close your eye for a minute or two so the ointment spreads.
4. Vision will be blurred for a short time – do not drive until it clears.

Continue the treatment as your doctor instructed, even if there is rapid improvement. If there is no improvement within a few days, or things get worse, see a doctor and do not switch ointments on your own. Do not use an eye ointment for more than 28 days after first opening, do not share it with family members, and do not use a tube left over from a previous treatment. On what you can buy without a prescription, see over-the-counter eye drops.

What to do if the ointment does not agree with you

Mild stinging and blurring for a few minutes after applying are common and usually pass. However, some situations call for stopping and seeking advice:

• A red, itchy, swollen eyelid that gets worse during treatment – this may be an allergic reaction to the ointment itself, and with Maxitrol mainly to neomycin. Continuing to apply it will only make it worse.
• Increasing pain, sensitivity to light or reduced vision – a sign that the problem is not a simple superficial infection, or that it is getting worse.
• An eye that improved on Maxitrol and got worse when you stopped – do not go back to the tube on your own; this is exactly the situation in which it is necessary to check what is happening under the steroid, including the eye pressure.
• Fever, sore throat or paleness during or after treatment with chloramphenicol – see a doctor, as described in the leaflet.

When to have your eyes examined

If you are torn between two ointments, it is probably not yet clear what the problem is – and that is exactly the question an examination answers. It is worth seeing an ophthalmologist when there is real pain in the eye, sensitivity to light, reduced vision, a red eye in a contact lens wearer, a history of herpes in the eye or glaucoma, or symptoms that do not improve within two or three days. Prof. Michael Mimouni, Director of the Cornea Unit at Rambam, sees patients at clinics in Herzliya Pituach and Haifa. A slit-lamp examination, including staining of the cornea and measurement of eye pressure when needed, makes it possible to tell whether there is an infection, inflammation or something else – and to choose the right treatment. Contact us to book an examination.

The information on this page is general and is not a substitute for a personal examination and medical advice. Diagnosis and treatment decisions are made only after a full eye examination. In the case of a chemical injury, severe pain or a sudden drop in vision, go to the emergency room immediately.