Physical dependence describes increased tolerance of a drug combined with a physical need of the drug to function. Abrupt cessation of the drug is typically associated with negative physical withdrawal symptoms.

Physical dependence is distinguished from addiction. While addiction tends to describe psychological and behavioral attributes, physical dependence is defined primarily using physical and biological concepts.

Symptoms

---

Persons physically dependent on a drug typically require larger doses of a drug over time to attain the same effect, a condition known as drug tolerance. Additionally, withdrawal of the drug produces symptoms including nausea, anxiety, hallucinations, body aches, and excessive sweating.

Drugs that cause physical dependence

---

• alcohol
• opiates such as morphine, heroin, codeine, and oxycodone
• benzodiazepines such as valium, lorazepam, alprazolam, and clonazepam
• barbiturates such as phenobarbital, amobarbital, and methylphenobarbital
• nicotine
• caffeine

Amphetamine and cocaine produce little or no physical dependence.

Treatment

---

Treatment for drug dependence depends upon the drug being withdrawn and often includes administration of another drug. For example, withdrawal symptoms associated with alcohol detoxification are often treated with tranquilizers known as benzodiazepines.

External links

---

• National Institutes of Health MedlinePlus Encyclopedia

References

---

• Drugs causing physical dependence taken from Merck Manual of Diagnosis and Therapy, Section 15, Chapter 195" Merck Manual.

Addiction