Strychnine is a source of accidental poisoning. Also used to study CNS mechanism because of its relatively specific action as a glycine antagonist.
Convulsion is characterized by opisthotonos , i.e., tonic extension of body and all limbs. Back is arched and only the back of the head and the heels are touching the touching the surface. All sensory stimuli produce exaggerated response and slight sensory stimulation may trigger convulsion.
The primary effects of an oral dose are wakefulness, alertness, decrease fatigue; mood elevation, increased ability to concentrate; an increase in motor and speech activity. Amphetamines also diminish the awareness of fatigue; person may push exertion to the point of severe damage or even death.
Caffeine, the most widely used drug in the world, is a stimulant. Commonly found in coffee, tea, soft drinks, chocolate and a wide variety of over-the-counter medications, it is legal to buy and easily accessible.
Cardiovascular System : Increase rate and force of the heart by directly stimulating myocardium (low doses) Tachycardia and arrhythmias at higher doses. Peripheral vasodilation decease in blood pressure (acute administration) Hypotension and cardiac arrest (rapid i.v. theophyline)
Chewing: with an-alkaloid material (South America)
Sniffing: hydrochloride salt -absorption: nasal mucous membranes -local vasoconstriction slows absorption and prolongs effect
Oral: large doses are needed for effect rapid onset
Smoking: cocaine is converted to alkaloid (freebase or "crack") which is readily volatilized undegraded at lower temperature. I.V. and smoking: reaches CNS in seconds in high concentration produces more immediate and intense effects