Psychoactive drugs are any chemical substance, natural or synthetic, which alters mood, and the level of perception or brain functioning. They may be classified by:
- Effects on the central nervous system (CNS)
- Legal status
- Therapeutic use
- Chemical structure
The CNS drug effects can be further divided into the following:
Depressants – decrease the activity of the central nervous system (CNS) and/or autonomic nervous system (ANS) including depression of respirations. Examples: sedative hypnotics such as alcohol, benzodiazepine and barbiturates, cannabinoids at low doses and opiates have various effects on the body mentally and physically.
Stimulants – increase the activity of the CNS and/or ANS. Examples: caffeine, nicotine, and cocaine, amphetamine and methamphetamine, prescribed amphetamine-like drugs, designer drugs such as pheylethylamines and methcathinone.
Hallucinogens – alter the state of consciousness frequently producing disturbances in thought and perception. Examples: indolealkylamines [such as Lysergic acid diethylamide (LSD), Dimethyltryptamine (DMT), magic mushrooms and morning glory], penylethylamines [such as mescaline, MDMA (ecstasy) and some derivatives], arycycloalkylamine [such as Phencyclidine (PCP), ketamine and cannabinoids at high dose].
Psychiatric medications –for the treatment of acute and chronic psychiatric disorders. Examples: psychotropic medication including antidepressants such as monoamine oxidase inhibitors (MAOI), tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRI); antipsychotics (such as Phenothiazine, Thioxanthene, and Risperidal) and mood stabilizers (e.g. Lithium, Tegretol).
Psychological and Physiological Effects of Depressants
Benzodiazepines- short term use at low to moderate doses
Benzodiazepines alleviate anxiety and have sedative and anticonvulsant properties. Common side effects of benzodiazepines: mild to moderate impairment of motor coordination, thinking and memory functions
drowsiness, lethargy or fatigue, confusion, depression, blurred vision, vertigo, tremors, slurred speech or stuttering, euphoria, nausea, constipation, dry mouth, loss of appetite, and less commonly, vomiting and diarrhea.
Benzodiazepine taken at a higher dose will result in sedation. As a result, the person may either appear to be intoxicated or even fall asleep. Common side effects at taking higher doses of benzodiazepines include mood swings, paradoxical excitement, erratic and hostile behaviors.
Opioids such as heroin (also morphine) produce analgesia, euphoria and respiratory depression. Depending on use and tolerance the effects may vary from person to person. Other effects may include: respiratory depression, nausea, vomiting, urinary retention, pin point pupils and suppression of the cough reflex. A common side effect is the decrease of gastrointestinal motility causing constipation.
Methadone is long acting synthetic opiate antagonist with a slow onset of action. Methadone maintenance therapy (MMT) has been shown to be effective in treatment of opiate substance dependence such as addiction to heroin and morphine. When taken orally it is readily absorbed, does not cause euphoric or sedating effects and does not result in continuing tolerance. Methadone can therefore be administered orally, once daily, at a relatively constant dose to reduce cravings for heroin and block the effects of opiate withdrawal symptoms.
Psychological and Physiological Effects of Stimulants
Cocaine – short term use in low doses
Cocaine acts on the CNS and sympathetic nervous system. It creates a sense of euphoria and can trigger a fight-or-flight response. The physiological effects are increased: alertness, heart rate, respiration, blood pressure and temperature. Other symptoms include dry mouth and a decrease in appetite and sleep. Behaviors from cocaine ‘high’ include: elation, euphoria, excitement, pressured speech or quiet contemplation and rapture, restlessness and grinding of teeth. When ingesting lower doses of cocaine, the person experiences an immediate “rush”, euphoria followed by periods of dysphoria experienced as anxiety and agitation.
Methamphetamine is a stimulant which acts on the CNS. D-methamphetamine hydrochloride (crystal meth) is more potent and causes more dependency than other forms of methamphetamine. It can be taken orally or rectally, injected, smoked, or snorted. The intensity and timing of the effect varies depending on how it is taken. Crystal meth causes feelings of euphoria; the person may feel powerful, have endless energy, increased productivity, enhanced sexual performance and a reduced appetite. Once the initial feeling wears off the person may experience anxiety, depression, mental confusion, fatigue, and headaches. The effects of crystal meth last longer than cocaine and can keep the person “up” for longer. Long term use of crystal meth increases a person’s tolerance causing them to require larger and more frequent doses for the desired effect. Prolonged use causes irritability, paranoia, violence, weight loss, psychosis known as “tweaking”. Extreme paranoia and violence may occur and the psychosis may become permanent or continue as flashbacks.
Street drugs are not controlled substances; this contributes to the risk of overdose due to the uncertainty of quality and strength of the substance as well as the combination of these drugs. High dose of depressants can cause the body to shut down by affecting brain function. High doses of stimulant can increase the affect of heart function by falsely causing the body to think it needs to work harder and faster to the point of exhaustion and collapse. If left untreated, it can be fatal.
Benzodiazepines are frequently involved in overdoses but are rarely the sole cause. They have a wide range in dose before they can become toxic which makes overdose difficult even if large quantities are ingested. However, an overdose of benzodiazepines is possible as it can cause respiratory depression.
Long term use of heroin decreases the effects felt by the user (tolerance) resulting in a need to increase the dose for the desired effect and the risk of overdose. A lethal dose of heroin affects level of unconsciousness and respiration so you will see the person lapsing in and out of consciousness (nodding) which may result in the person possibly aspirating on their own vomit or slowly going into respiratory arrest.
Cocaine overdose has no known antidote so overdosing on cocaine is fatal. A lethal dose of cocaine depends on a person’s tolerance, method of use and any underlying medical condition. The effects of a cocaine overdose are: cardiac arrhythmias, seizures, intracranial hemorrhage (bleeding in the brain), hyperthermia or respiratory arrest.
Poly drug overdose
A poly drug overdose involves a combination of drugs. Combinations of CNS depressants such as alcohol, opiates, benzodiazepines, methadone, barbiturates, psychotropic medications and/or antiepileptic together enhance each other’s depressant effect. Long acting substances like methadone, benzodiazepines and alcohol increase the risk of overdose when introducing heroin to the combination.
Recognizing an overdose
Often it is hard to identify when an overdose is happening. Being able to identify certain characteristic of an overdose will aid in providing the correct type of care required to assist someone in an overdose. Being able to recognize when someone is “on the nod” or “dropping” is essential. Nodding is recognized when someone appears to be falling asleep but can be roused when called by their name or by physical stimulation such as shaking them by their shoulders. Someone who has “dropped” cannot be woken up by any stimulation and are unresponsive (unconscious). Overdosing at times can be obvious. When someone has just taken a shot and immediately “drops”, is unresponsive, experiencing slow shallow breaths or not breathing at all, and/or cyanotic (turning blue) they are overdosing. Unfortunately, poly drug overdose can be less apparent as it sometimes is a slower process. The person may slowly become unconscious but appear like they are sleeping while their breathing slowly stops.