prescription shampoos - all the same?
For as long as i can remember, ive had very dry skin on my scalp, ive tried all sorts and had more or less given up until my doctor suggested a ketoconazole shampoo. I wasnt convinced because i had tried them before, however the one i ended up with was perfect, totally solved the problem. It was called Ketopine.
When i ran out, i was given another prescription for ketoconazole shampoo, this time though, the pharmacist gave me Nizoral, and within a few days i have a bad scalp again.
Although they both have the same amount of ketaconazole in them, their ingredients vary.
Is it possible that something in the Nizoral is irritating my scalp or should they both be the same?
Thanks

Yes - the Nizoral formula could have a preservative that is irritating your scalp. Go back to the pharmacy & explain what happened. You might be able to exchange the shampoo for your preferred brand. In future, ask your derm to specify the brand on your prescription.
I have a sensitive scalp & avoid shampoos that have quartinium-15 or DMDM hydantoin. These preservatives release formaldehyde that is a proven skin irritant.