Amphetamines Methylphenidate

The development of psychosis is the most striking clinical characteristic of high-dose stimulant abuse. The amphetamines, methylphenidate, and phen-metrazine all produce psychosis (Ellinwood et al. 1973 Harris and Batki 2000 Iversen et al. 1978 Lucas and Weiss 1971 McCormick and McNeil 1962). 

In rats, cocaine (6 mg/kg, i.p. or p.o.) has been shown to induce a significant increase in sleep latency and a reduction in total sleep time, including a decrease in both non-REM sleep and REM sleep (Schwartz 2004). In humans, cocaine, amphetamines, and methylphenidate also produce decreases in sleepiness, an increased latency to sleep, and a marked decrease in REM sleep associated with an increased latency to the onset of this state. Amphetamine, methylphenidate, and cocaine are known to act by enhancing the amount of the monoamines available within the synaptic cleft of synapses in the CNS. 

Lin J. S., Hou Y., Jouvet M. (1996). Potential brain neuronal targets for amphetamine-, methylphenidate-, and modafinil-induced wakefulness, evidenced by c-fos immunocytochemistry in the cat. Proc. Natl. Acad. Sci. USA 93, 14128-33. 

To a lesser extent than the amphetamines, methylphenidate is sometimes abused, though this is a risk to be balanced against the risk of the untreated disease state. 

Ritalin An amphetamine (methylphenidate) in widespread use for treating hyperactivity or Attention Deficit Disorder (ADD) in children because of... 

FIGURE 7—53- Heroic combo 9 Mirtazapine plus stimulant. Here, 5HT, NE, and DA are all single-boosted. The stimulants could include ( -amphetamine, methylphenidate, phentermine, or di-ethylpropion. It could also include direct-acting dopamine agonists such as pramipexole. 

Other possible pharmacological causes of sleep disturbance in the medically ill should also be considered, including high-potency diuretics or drugs with CNS stimulant activity (e.g.., caffeine, amphetamines, methylphenidate, and newer stimulants)... 

One of the most controversial CNS-acting drugs in contemporary society is methylphenidate (Ritalin ). This drug is structurally related to amphetamine and is a mild stimulant that has abuse potential similar to amphetamine. Methylphenidate is classified as a Schedule II controlled substance. It is effective in the treatment of narcolepsy and attention-deficit hyperactivity disorder (ADHD). Its use in ADHD has caused the greatest controversy. 

Central nervous system stimulants, e.g., amphetamine, methylphenidate (Ritalin) and cocaine... 

Hypertensive crisis with headache, intracranial bleeding, and death may result from combining MAO inhibitors with sympathomimetic drugs (e.g., amphetamines, methylphenidate, cocaine, dopamine, epinephrine, norepinephrine, and related compounds methyidopa,... 

Methylphenidate releases stored dopamine but most of its action is to irrhibit uptake of central neurotransmitters. Its effects and adverse effects are very similar to amphetamines. Methylphenidate has a low systemic availability and slow onset of... 

A drug similar in structure and effect to the amphetamines, methylphenidate (Ritalin ), and phenylpropanolamine, a stimulant vasoconstrictor that shows up in many cough and cold remedies, should also be mentioned. The most insidiously dangerous stimulant, nicotine as found in tobacco, is discussed briefly as well. 

Many drugs used for recreational as well as medical purposes can stimulate the central nervous system and so are referred to as stimulants. We separate. stimulants into tsvo groups according to their legal and social status. Controlled stimulants such as cocaine, amphetamines, methylphenidate (Ritalin), and related compounds are treated in this chapter, and over-the-counter stimulants such as nicotine and caffeine are dealt with in Chapters 7 and 8. We first consider the hi.story of stimulant use and discuss some of the effects of cocaine and the amphetamines as we review their history. Then we turn to a more detailed treatment of the pharmacology of these stimulants. 

Controlled stimulants that are frequently abused include amphetamines, methylphenidate, metham-phetamine, and cocaine. Amphetamine, methamphet-amine, methylphenidate, and cocaine can be smoked, inhaled, ingested, and injected. Methamphetamine s effects can last up to 6 h. Methylphenidate (Ritalin) is a sustained release product and can last up to 12 h. Cocaine s effects last only about 1 h. These drugs have significant potential for abuse and addiction. 

Antidepressants selective serotonin reuptake inhibitors, tricyclic antidepressants Antihypertensives felodipine Antibiotics quinolones, isoniazid Bronchodilators albuterol, theophylline Corticosteroids prednisone Dopa agonists levodopa Herbals ma huang, ginseng, ephedra Nonsteroidal anti-inflammatory drugs ibuprofen Stimulants amphetamines, methylphenidate, caffeine, cocaine Sympathomimetics pseudoephedrine Thyroid hormones levothyroxine Toxicity anticholinergics, antihistamines, digoxin Withdrawal alcohol, sedatives... 

Methylphenidate is a piperidine derivative that is structurally related to amphetamine. Methylphenidate (Ritalin, others) is a mild CNS stimulant with more prominent effects on mental than on motor activities. However, large doses produce signs of generalized CNS stimulation that may lead to convulsions. Its pharmacological properties are essentially the same as those of the amphetamines. 

Concomitant use with amphetamines, methylphenidate, or pemoline may induce Tourette-like tics and may exacerbate existing tics. 

II Medical use high addiction potential Strong opioid agonists, cocaine, short half-life barbiturates, amphetamines, methylphenidate... 

Amphetamines methylphenidate cocaine Agitation, hypertension, tachycardia, delusions, hallucinations, hyperthermia, seizures, death Apathy, irritability, increased sleep time, disorientation, depression... 

Serum levels of clonazepam are decreased by the enzyme-inducing properties of phenobarbitai, phenytoin, and CBZ. Concurrent administration of amphetamines, methylphenidate, ethanol, antianxiety drugs, or antipsychotics may cause CNS depression or altered respiration. The combined administration of clonazepam and valproate may cause absence status, and in patients displaying a mixed seizure pattern, clonazepam may precipitate grand mal seizures. 

Examples of Schedule II drugs are opiates and opioids (narcotics)—straight opiates of codeine, morphine, meperidine stimulants—amphetamine, methylphenidate depressants— amobarbital, pentobarbital, secobarbital, or any combination, that is, Tuinal hallucinogenic substances and any immediate precursors. 

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