Few and mild adverse events were seen.
Mild adverse reactions were reported in a small percentage of cases, including injection site reactions, fever, and rash.
Forty-one articles (29.71%) reported mild adverse events with TCPMs but these occurred infrequently.
Even the mild adverse skin effects are frequently cited as reasons for discontinuation.
Mild adverse events related to gastrointestinal system were observed in the trial, which subsided spontaneously.
"Imagine you have a drug where mild adverse effects are documented and hopefully rare adverse effects are being reported in case reports," said Ernst.
"In addition to these fairly mild adverse effects, which basically are pain at the site of manipulation and referred pain sometimes, which only lasts one or two days, we have about 500-700 cases of severe complications being reported".
A high level of quinine in the plasma frequently is associated with cinchonism, a mild adverse reaction associated with such symptoms as a ringing noise in the ears (tinnitus), headache, nausea, abdominal pain, and visual disturbance.
Some of the transdermal products are associated with mild adverse skin effects such as redness and irritation, but more severe and bothersome consequences include blistering and tattooing.
Five patients suffered mild adverse effects (moon face and hirsutism) between week 4 and week 6 of treatment, which were speedily reversed by reducing the frequency of mouthwash.
Mild adverse reactions included pain, numbness or dizziness following injections.
