Quinine London. It remained the antimalarial drug of choice until the 1940s, when other drugs took over. The form of quinine most effective in treating malaria was found by Charles Marie de La Condamine in 1737. In 1820, French researchers Pierre Joseph Pelletier and Joseph Bienaimé Caventou first isolated quinine from the bark of a tree in the genus "Cinchona" - probably "Cinchona officinalis" - and subsequently named the substance. The name was derived from the original Quechua (Inca) word for the cinchona tree bark, "quina" or "quina-quina", which means "bark of bark" or "holy bark". Prior to 1820, the bark
Analgesic tolerance, which may be of particular concern regarding patients suffering with chronic pain and requiring an analgesic over long periods. Opioid tolerance is often addressed with opioid rotation therapy in which a patient is routinely switched between two or more non-cross-tolerant opioid medications in order to prevent exceeding safe dosages in the attempt to achieve an adequate analgesic effect. Opioid tolerance should not be confused with opioid-induced hyperalgesia. The symptoms of these two conditions can appear very similar but the mechanism of action is different. Opioid-induced hyperalgesia is when exposure to opioids increases the sensation of pain (hyperalgesia) and can