Stimulants

Tobacco

Mechanism

1. Enter bloodstream → Stimulates adrenal glands → adrenaline → Stimulates CNS → ↑ BP, Respiration, HR.
2. Lead to the release of glucose → Suppressed insulin excretion → chronically elevated blood glucose.
3. Increase the level of Dopamine.
4. Addiction results from long-term brain changes.

Mental Disorders Due to Use of Stimulants

• Cocaine, amphetamine, methamphetamine (pervitine), phenmetrazine, methyphenidate, MDMA (ecstasy, methylenedioxymethamphetamine).
• Positive mood, activity, planning, diminished need of sleep.
• Tachycardia, arrhythmia, hypertension, hyperthermia, intracerebral hemorrhage.
• Withdrawal symptoms: severe craving, depression, decreased energy, fatigue, sleep disturbance.
• Prolonged use can trigger paranoid psychoses, impulsivity, aggressivity, irritability, suspiciousness, and anxiety states.

Amphetamines

Psychopharmacology

• D and L enantiomers have different effects. Direct and indirect sympathomimetics (mostly cause vesicular release of DA or NA).

Adverse Effects

• CVA, cardiac (MI, HTN), GI ischemic colitis, HIV/hepatitis.

• Designer amphetamines (which also have 5HT properties) increase use.

• Rx indications

  • ADHD, narcolepsy, depression +/- augmentation

• Amphetamines and amphetamine-related drugs are central nervous system stimulants.

• The past decade has seen a marked increase in the popularity of amphetamine use.

Types

• Amphetamines – group substances including predominantly amphetamine and methamphetamine.

• Ecstasy- group substances- including MDMA (3,4-Methylenedioxymethamphetamine) and its analogs.

Effects of Abuse

1. Short term
   • Loss of appetite, rapid breathing and heartbeat, high blood pressure, and dilated pupils.
   • Fever, sweating, headache, blurred vision, and dizziness (high dose).
   • Flushing, pallor, very rapid or irregular heartbeat, tremors, loss of coordination, and collapse (very high dose).
   • death
2. Long term effects
   • Short-term effects are exaggerated.
   • Various illnesses are related to vitamin deficiencies and malnutrition.
   • More prone to illness.
   • Amphetamine psychosis – a mental disturbance similar to paranoid schizophrenia.
   • Kidney damage, lung problems, strokes, or other tissue injury may result.

Chronic Use

• Tolerance can develop. Abusers sometimes forego food and sleep in a form of binging known as a “run,” injecting as much as 1 gm q 2-3 hrs over several days until the user runs out of the drug or is too disorganized to continue.
• Chronic abuse can lead to psychotic behavior, characterized by intense paranoia, visual and auditory hallucinations, and out-of-control rages that can be coupled with extremely violent behavior.
• As much as 50 percent of the dopamine-producing cells in the brain can be damaged after prolonged exposure to relatively low levels of methamphetamine. Serotonin-containing nerve cells may be damaged even more extensively. Whether this toxicity is related to the psychosis is unknown.
• Psychotic syndrome
  • Similar (paranoia, perceptual abnormalities) to SCZ except for increased VHs, appropriate affect, hyperactivity, hypersexuality, confusion/incoherent but usually no thought disorder.
  • Rx: haldol
• Withdrawal Symptoms
  • Due to tolerance to some effects.
  • Become psychologically or physically dependent.
  • Fatigue, long but troubled sleep, irritability, intense hunger, and moderate to severe depression, which may lead to suicidal behavior.
  • Fits of violence may also occur.
  • These disturbances can be temporarily reversed if the drug is taken again.