Withdrawal symptoms heroin

Sudden withdrawal of clonidine from patients on antihypertensive therapy produce symptoms clinically similar to opiate withdrawal. These include headache, nervousness, tachycardia, stomach pains, and sweating. It may be this apparent similarity that gave someone the idea to treat heroin withdrawal symptoms with clonidine. It seems to work with some addicts and is now experimental for this application. 

Cross-tolerance A condition where an individual who is tolerant to the pharmacological effects of one member of a drug family also shows tolerance to other members of that family. Cross-dependence allows drug substitution during detoxification (e.g., methadone for heroin or clomethiazole for ethanol), so reducing the severity and potential danger of withdrawal symptoms. 

Methadone has oral efficacy, extended duration of action, and ability to suppress withdrawal symptoms in heroin addicts. With repeated doses, the analgesic duration of action of methadone is prolonged, but excessive sedation may also result. Although effective for acute pain, it is usually used for chronic cancer pain. 

Unnecessary detoxification with drugs should be avoided if possible (e.g., if symptoms are tolerable). Heroin withdrawal reaches a peak within 36 to 72 hours, and methadone withdrawal peak is reached at 72 hours. 

Acute abstinence syndrome (withdrawal) - In chronic pain patients in whom opioid analgesics are abruptly discontinued, anticipate a severe abstinence syndrome. This may be similar to the abstinence syndrome noted in patients who withdraw from heroin. Severity is related to the degree of dependence, the abruptness of withdrawal, and the drug used. Generally, withdrawal symptoms develop at the time the next dose would ordinarily be given. 

Mechanism of Action An opioid agonist-antagonist that binds with opioid receptors in the CNS. Therapeutic Effect Alters the perception of and emotional response to pain blocks the effects of heroin and produces minimal opioid withdrawal symptoms. Pharmacokinetics Rapidly absorbed following IM administration. Protein binding Very high. Metabolized in liver. Primarily excreted in feces minimal excretion in urine. Half-life 2 hr... 

The answers are 264-c, 263-c. (Katzung, pp 519, 535-537.) Heroin and other opioids (such as morphine and meperidine) exhibit a high degree of tolerance and physical dependence. The tolerance rate magnitudes to all of the effects of opioids are not necessarily the same. The physical dependence is quite clear from the character and severity of withdrawal symptoms, which include vomiting spasms, abdominal cramps, diarrhea, and acid-base imbalances among others. 

The overall effect that heroin has is to depress the body s central nervous system. However, other short-term effects include a brief euphoria, reduced pain, sedation/drowsiness, reduced anxiety, and reduced respiration. Because of its potent nature, addiction to heroin occurs rapidly. Once addicted, the user craves heroin about five hours after their last injection. The withdrawal symptoms of heroin are also acute and occur about 10 hours after the last use. Withdrawal symptoms progress in intensity and severity over the next three days and only slowly subside after about 10 days. Ultimately, the user is left with a psychological addiction that may take months or even years to overcome. 

Suppression of heroin self-administration in opioid-dependent volunteers has been found to be greater at doses over lOOmg (Donny et al. 2005), and this relates to the three-level effects of methadone, the implications of which we often have to contend with in our discussions with patients. Basically low doses of methadone will suppress opiate withdrawal symptoms in dependent individuals, and this is what a lot of patients mean when they say that their dose (which may be considered too low by us) holds them. In medium to high levels of methadone there is less craving for opiates, and then at the highest doses there will be full narcotic blockade (Donny et al. 2002), but as already indicated the users themselves may not wish to take such dosages. 

His problem over the past year has been heroin, on which he became dependent following initial experimental use. After about three months he would get withdrawal symptoms if he did not have the drug daily, and his usage stabilized at 0.5g per day, by smoking. He resented the control which heroin had gained over his life, and he could see that his general health was suffering. He told us I m sick of heroin and I just want off it . 

As indicated, buprenorphine can offer a quicker option than methadone, with a three-day course reported to be effective for withdrawal from heroin (Cheskin et al. 1994). The side-effects of clonidine which render it unsuitable for community treatment can be manageable in the inpatient setting, although the drug is being superseded by lofexidine where that is available. Controlled studies have found clonidine and lofexidine to be equally effective in alleviating withdrawal symptoms in inpatient detoxification from heroin (Lin et al. 1997) and from methadone (Khan et al. 1997), with lofexidine resulting in less hypotension and fewer adverse effects. Another double-blind controlled study found lofexidine to be broadly as effective as a ten-day methadone detoxification in inpatient opiate withdrawal (Bearn et al. 1996). 

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