Physical dependence is a physical condition caused by the chronic use of tolerance-forming drugs, where sudden or gradual drug withdrawal causes unpleasant physical symptoms. Physical dependence may develop from the use of therapeutic low-dose certain drugs such as benzodiazepines, opioids, antiepileptics and antidepressants, as well as substance abuse such as alcohol, opioids, and benzodiazepines. The higher the dosage used, the greater the duration of use, and earlier age use begins is a predicted worsening of physical dependence and thus a more severe withdrawal syndrome. The acute withdrawal syndrome may take several days, weeks or months. The prolonged withdrawal syndrome, also known as the post-acute-withdrawal syndrome or "PAWS", is a low-grade continuation of some of the acute withdrawal symptoms, usually in the pattern of remitting-relaps, often resulting in recurrence and prolonged inability of the degree to impede the possibility of legitimate employment. A long withdrawal syndrome can last for months, years, or depending on individual factors, indefinitely. The prolonged withdrawal syndrome is noted most often due to benzodiazepines. To eliminate the popular misas association with addiction, physical dependence on drugs is sometimes compared to dependence on insulin by people with diabetes.
Video Physical dependence
Symptoms
Physical dependence can manifest itself in the appearance of both physical and psychological symptoms caused by physiological adaptations in the central nervous system and the brain due to chronic exposure to a substance. Symptoms that may be experienced during withdrawal or dose reduction include increased heart rate and/or blood pressure, sweating, and tremors. More serious withdrawal symptoms such as confusion, convulsions, and visual hallucinations indicate a serious emergency and the need for immediate medical care. Hypnotic tranquilizers such as alcohol, benzodiazepines, and barbiturates are the only commonly available substances that can be fatal in withdrawal due to their tendency to induce seizure withdrawal. The sudden withdrawal of other drugs, such as opioids, can lead to painful withdrawals that are very rarely fatal in good general medical patients and with medical care, but more often fatal in patients with weakened cardiovascular systems; toxicity is generally caused by an increase in heart rate and frequent extreme blood pressure (which can be treated with clonidine), or due to arrhythmias due to electrolyte imbalance caused by an inability to eat, and persistent diarrhea and vomiting (which can be treated with loperamide and ondansetron respectively) associated with acute opioid withdrawal, especially in longer-acting substances where diarrhea and emesis can continue for weeks, although life-threatening complications are very rare, and almost nonexistent with appropriate medical management.
Maps Physical dependence
Treatment
Treatment for physical dependence depends on the drug being withdrawn and often includes the administration of other drugs, especially for substances that can be dangerous when suddenly stopped or when previous attempts have failed. Physical dependence is usually managed by slow dose reductions over weeks, months or sometimes longer depending on medications, doses and individuals. Physical dependence on alcohol is often administered with cross-tolerant drugs, such as long-acting benzodiazepines to manage alcohol withdrawal symptoms.
Drugs that cause physical dependency
- All Ã,Âμ-opioids with an agonist effect (even slightly), such as (partial list) of morphine, heroin, codeine, oxycodone, buprenorphine, nalbuphine, methadone and fentanyl, but not agonists specific to non-μμ opioid receptors, such as salvinorin A (k-opioid agonist), or an opioid antagonist or inverse agonist, such as naltrexone (opioid inverse opioid universal)
- All GABA agonists and positive allosteric modulators of the GABA-A ionotropic receptor and metabotropic receptor subunit of GABA-B include (partial list):
- alcohol (alcoholic beverages) (see alcohol dependence, alcohol withdrawal, delirium tremor)
- barbiturates such as phenobarbital, sodium thiopental, and secobarbital benzodiazepines such as diazepam (Valium), lorazepam (Ativan), and alprazolam (Xanax) (see benzodiazepine dependence and benzodiazepine withdrawal syndrome)
- nonbenzodiazepine hypnotics (z-drugs) such as zopiclone and zolpidem.
- gamma-hydroxybutyric acid (GHB) and 1,4-butanediol
- carisoprodol (Soma) and related carbamates (tybamat and meprobamate)
- baclofen (Lioresal) and its non-chlorinated analogue fenibut
- kloral hydrate
- glutethimide
- clomethiazole
- methaqualone (Quaalude)
Rebound syndrome
A variety of drugs while not causing actual physical dependence can still cause withdrawal symptoms or rebound effects during dose reduction or sudden or rapid withdrawal. These can include caffeine, stimulants, steroid drugs and antiparkinson drugs. It is debatable if all classes of antipsychotic medications cause actual physical dependence, if only a few do, or if none, but all, if stopped too quickly, cause acute withdrawal syndrome. When talking about withdrawal of drugs, especially with stimulants, it is sometimes referred to as "down" or "crashing".
Some drugs, such as anticonvulsants and antidepressants, describe the drug category and not the mechanism. Individual agents and drug classes in the anticonvulsant drug category act on many different receptors and are unlikely to generalize their potential for physical dependence or the incidence or severity of the rebound syndrome as a group so that they should be viewed individually. Anticonvulsants as a group but are known to cause tolerance to anti-seizure effects. SSRI drugs, which have important uses as antidepressants, cause syndrome cessation that manifests with physical side effects. For example, There is a case report of discontinuation syndrome with venlafaxine (Effexor).
See also
- Addiction
- Alcohol withdrawal syndrome
- Benzodiazepine dependency
- Benzodiazepine withdrawal syndrome
- Termination syndrome
- Drug tolerance
- Psychological dependency
- Rebound insomnia
- Substance dependency
References
External links
- National Institutes of Health MedlinePlus Encyclopedia
Source of the article : Wikipedia
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