Which different groups of hallucinogenic drugs are known?

Classic hallucinogens (LSD)

Dissociative drugs (PCP)

Name a few typical effects of the hallucinogenic drugs and discuss the clinical profile of a patient who had taken them.

Psychosis, lack of judgment which leads to reckless behavior and sensory distortion which is mainly visual.

Patients experience a completely different reality which is due to the hallucinogens psychedelic effects.

Somatic effects include nausea, weakness and paresthesia. Panic reactions are also prone to occur. 

Someone who has taken hallucinogens will present with; 

Tachycardia, hypertension, and hyperthermia. 

Sympathomimetic effects include mydriasis, sweating, ataxia, and vomiting. 

A mental status examination must be done to determine the affect on speech, appearance, presence of auditory/visual hallucinations, delusional thinking, and suicidal/homicidal ideation should be carefully assessed.

Although nystagmus in any direction can occur with PCP use, rotatory nystagmus is a classic sign.

How is an over-dose of LSD dealt with? 

Benzodiazepines (phenobarbital,diazepam) are given to calm them, reduce agitation and normalize the operation of the CNS. 

Anti-epileptics are administered for convulsions. 

Chlorpromazine is given to eliminate the hallucinogen and to bring back consciousness.

For vomiting, and antiemetic, metoclopramide can be given. 

Other sources explain the treatment to be;

• Ergotism therapy: IV administration of anticoagulants, vasodilators and sympatholytics could be useful. 
• Rehabilitation and supportive care (respiratory support)

How is an over-dose of anticholinergic drugs dealt with?

Reversible ACh inhibitor: physostigmine.

Benzodiazepine can also be given.