Wednesday 29 August 2012

Hydromorphone

Hydromorphone, a more common synonym for dihydromorphinone, commonly a hydrochloride (brand names Palladone, Dilaudid, and numerous others) is a very potent centrally acting analgesic drug of the opioid class. It is a derivative of morphine, to be specific, a hydrogenated ketone thereof, and it can be said that hydromorphone is to morphine as hydrocodone is to codeine and, therefore, a semi-synthetic drug. It is, in medical terms, an opioid analgesic and, in legal terms, a narcotic. Hydromorphone is commonly used in the hospital setting, mostly intravenously (IV) because its bioavailability orally, rectally, and intranasally is very low.

Morphine

Morphine is the most abundant alkaloid found in opium, the dried sap (latex) derived from shallowly slicing the unripe seedpods of the opium, or common and/or edible, poppy, Papaver somniferum. Morphine was the first active principle purified from a plant source and is one of at least 50 alkaloids of several different types present in opium, poppy straw concentrate, and other poppy derivatives. Morphine is generally 8 to 14 percent of the dry weight of opium,although specially bred cultivars reach 26 percent or produce little morphine at all, under 1 percent, perhaps down to 0.04 percent. The latter varieties, including the 'Przemko' and 'Norman' cultivars of the opium poppy, are used to produce two other alkaloids, thebaine and oripavine, which are used in the manufacture of semi-synthetic and synthetic opioids like oxycodone and etorphine and some other types of drugs. P. bracteatum does not contain morphine or codeine, or other narcotic phenanthrene-type, alkaloids. This species is rather a source of thebaine.Occurrence of morphine in other Papaverales and Papaveraceae, as well as in some species of hops and mulberry trees has not been confirmed. Morphine is produced most predominantly early in the life cycle of the plant. Past the optimum point for extraction, various processes in the plant produce codeine, thebaine, and in some cases negligible amounts of hydromorphone, dihydromorphine, dihydrocodeine, tetrahydro-thebaine, and hydrocodone (these compounds are rather synthesized from thebaine and oripavine). The human body produces endorphines, which are endogenous opioid peptides that function as neurotransmitters and have similar effects

Opiates and morphinomimetics

Morphine, the archetypal opioid, and various other substances (e.g. codeine, oxycodone, hydrocodone, dihydromorphine, pethidine) all exert a similar influence on the cerebral opioid receptor system. Buprenorphine is thought to be a partial agonist of the opioid receptor, and tramadol is an opiate agonist with SNRI properties.Tramadol is structurally closer to venlafaxine than to codeine and delivers analgesia by not only delivering "opiate-like" effects (through mild agonism of the mu receptor) but also by acting as a weak but fast-acting serotonin releasing agent and norepinephrine reuptake inhibitor.Dosing of all opioids may be limited by opioid toxicity (confusion, respiratory depression, myoclonic jerks and pinpoint pupils), seizures (tramadol), but there is no dose ceiling in patients who accumulate tolerance.

COX-2 inhibitors

These drugs have been derived from NSAIDs. The cyclooxygenase enzyme inhibited by NSAIDs was discovered to have at least 2 different versions: COX1 and COX2. Research suggested that most of the adverse effects of NSAIDs were mediated by blocking the COX1 (constitutive) enzyme, with the analgesic effects being mediated by the COX2 (inducible) enzyme. The COX2 inhibitors were thus developed to inhibit only the COX2 enzyme (traditional NSAIDs block both versions in general). These drugs (such as rofecoxib, celecoxib and etoricoxib) are equally effective analgesics when compared with NSAIDs, but cause less gastrointestinal hemorrhage in particular.After widespread adoption of the COX-2 inhibitors, it was discovered that most of the drugs in this class increased the risk of cardiovascular events by 40% on average. This led to the withdrawal of rofecoxib and valdecoxib, and warnings on others. Etoricoxib seems relatively safe, with the risk of thrombotic events similar to that of non-coxib NSAID diclofenac.

Paracetamol and NSAIDs

The exact mechanism of action of paracetamol/acetaminophen is uncertain, but it appears to be acting centrally rather than peripherally (in the brain rather than in nerve endings). Aspirin and the other non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenases, leading to a decrease in prostaglandin production. This reduces pain and also inflammation (in contrast to paracetamol and the opioids).
Paracetamol has few side effects and is regarded as safe, although intake above the recommended dose can lead to liver damage, which can be severe and life-threatening, and occasionally kidney damage. While paracetamol is usually taken orally or rectally, an intravenous preparation introduced in 2002 has been shown to improve pain relief and reduce opioid consumption in the perioperative setting.

Analgesic

An analgesic (also known as a painkiller) is any member of the group of drugs used to relieve pain (achieve analgesia). The word analgesic derives from Greek αν - ("without") and άλγος - ("pain").
Analgesic drugs act in various ways on the peripheral and central nervous systems; they include paracetamol (para-acetylaminophenol, also known in the US as acetaminophen), the non-steroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, and opioid drugs such as morphine and opium. They are distinct from anesthetics, which reversibly eliminate sensation.In choosing analgesics, the severity and response to other medication determines the choice of agent; the WHO pain ladder, originally developed in cancer-related pain, is widely applied to find suitable drugs in a stepwise manner.The analgesic choice is also determined by the type of pain: for neuropathic pain, traditional analgesics are less effective, and there is often benefit from classes of drugs that are not normally considered analgesics, such as tricyclic antidepressants and anticonvulsants.

Monday 14 May 2012

Individual Vs Group risk

Individual risk is the risk that affects the economy.
Example : earthquakes, floods, wars, unemployment etc.

Where as,
Group risk is the risk persisting over a group.
Example : theft, robbery, fire etc.