Cinchona in the year 1851. Mr. [Thaddäus] Haenke mentioned the existence of cinchona bark on his visit to Yuracares in 1796". (Source: Exploration of the Valley of the Amazon, by Lieut. Lardner Gibbon, USN. Vol.II, Ch.6, pp. 146-47.) The cultivation of cinchona led from the 1890s to a decline in the price of quinine but the quality and production of raw bark by the Dutch in Indonesia led them to dominate world markets. The producers of processed drugs in Europe (especially Germany) however bargained and caused fluctuations in prices which led to a Dutch-led Cinchona Agreement in 1913 that ensured a
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