THE CASE
The Therapeutic Goods Administration (TGA) has recently issued an alert for the oral antifungal drug terbinafine, sold in Australia under many brand names including Lamisil by Novartis (see NOTES below). The TGA reported that three people had died and about seventy others had suffered significant liver damage.
Terbinafine is oficially indicated to treat adults with ringworm when topical treatment has been tried not worked. It is also used to treat fungal nail infections. These are hardly life threatening conditions, so a doctor should not prescribe terbinafine lightly. Apart from sometimes (the manufacturer says rarely) causing liver problems, tebinafine also ocassionally causes a whole gamut of side-effects including blood abnormalities, raised cholesterol, skin rashes, muscle pains, headache and nausea. It might also cause kidney abnormalities and retinal abnormalities.
The conditions for prescribing terbinafine under the Australian Pharmaceutical Benefits Scheme (PBS) medicine are:
Death is a particularly unsatisfactory outcome for a patient undergoing treatment for a relatively minor skin infection. The TGA warning concludes:
Other regulatory authorities around the world are now watching terbinafine following the TGA warning.
If you are taking terbinafine and develop fever, sore throat, mouth ulcers, "flu-like" symptoms (chills, aching joints, swollen glands, lack of energy) any other signs of infection tell your doctor immediately. Make sure to have any blood tests done that are ordered by your doctor, these tests are used detect side effects on your liver, kidneys and blood.
MY VERDICT
Oral terbinafine should only be used once ALL possible alternatives have been vigorously tried. It would be better for GPs to refer patients to Dermatologists than to experiment with oral terbinafine. It is simply not worth the risk.
None of this applies to the topical forms of terbinafine such as Lamisil Cream and Lamisil DermGel both also marketed by Novartis. A patient is unlikely to absorb enough terbinafine through the skin to cause systemic side-effects.
The TGA were awake this time- congratulations!
NOTES
Brands of oral terbinafine marketed in Australia are Lamisil, Tamsil, Terbihexal, Terbinafine GenRx, Terbinafine-DP, Terbinafine Pharmacor and Zabel.
The Therapeutic Goods Administration (TGA) has recently issued an alert for the oral antifungal drug terbinafine, sold in Australia under many brand names including Lamisil by Novartis (see NOTES below). The TGA reported that three people had died and about seventy others had suffered significant liver damage.
Terbinafine is oficially indicated to treat adults with ringworm when topical treatment has been tried not worked. It is also used to treat fungal nail infections. These are hardly life threatening conditions, so a doctor should not prescribe terbinafine lightly. Apart from sometimes (the manufacturer says rarely) causing liver problems, tebinafine also ocassionally causes a whole gamut of side-effects including blood abnormalities, raised cholesterol, skin rashes, muscle pains, headache and nausea. It might also cause kidney abnormalities and retinal abnormalities.
The conditions for prescribing terbinafine under the Australian Pharmaceutical Benefits Scheme (PBS) medicine are:
"Proximal or extensive (greater than 80% nail involvement) onychomycosis due to dermatophyte infection where topical treatment has failed. This infection must be proven by microscopy or culture and confirmed by an Approved Pathology Authority. The date of the pathology report must be provided at the time of application and must not be more than 12 months old."Because the conditions being treated are relatively trivial, and the (addmittedly rare) potential consequences are so dire, a prescriber should consider the risk/benefit ratio every time terbinafine is prescribed. The TGA gives an example with this case:
"One patient, a 79 year old female developed agranulocytosis about 2 months after initiation of terbinafine, and died from septic shock despite treatment with granulocyte colony stimulating factor and antibiotics."
Death is a particularly unsatisfactory outcome for a patient undergoing treatment for a relatively minor skin infection. The TGA warning concludes:
"Patients taking terbinafine for longer than a month should be advised to be alert for any symptoms of possible infection/neutropenia, such as fever, sore throat or mouth ulcers. Total white blood cell count and neutrophil count should be checked if symptoms develop since a delay in diagnosis is likely to be associated with an increase in morbidity and mortality."
Other regulatory authorities around the world are now watching terbinafine following the TGA warning.
If you are taking terbinafine and develop fever, sore throat, mouth ulcers, "flu-like" symptoms (chills, aching joints, swollen glands, lack of energy) any other signs of infection tell your doctor immediately. Make sure to have any blood tests done that are ordered by your doctor, these tests are used detect side effects on your liver, kidneys and blood.
MY VERDICT
Oral terbinafine should only be used once ALL possible alternatives have been vigorously tried. It would be better for GPs to refer patients to Dermatologists than to experiment with oral terbinafine. It is simply not worth the risk.
None of this applies to the topical forms of terbinafine such as Lamisil Cream and Lamisil DermGel both also marketed by Novartis. A patient is unlikely to absorb enough terbinafine through the skin to cause systemic side-effects.
The TGA were awake this time- congratulations!
NOTES
Brands of oral terbinafine marketed in Australia are Lamisil, Tamsil, Terbihexal, Terbinafine GenRx, Terbinafine-DP, Terbinafine Pharmacor and Zabel.
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