Intravenous injection irritant solutions

Intramuscular injection (IM) Rapid from aqueous solution Easier to inject than intravenous injection Irritating drugs may be very painful... 

A 34-year-old woman with a history of polysubstance dependence (alcohol, cannabis, and cocaine), depressive episodes associated with multiple suicide attempts, and borderline personality disorder, who had been incarcerated after conviction on charges of physical assault and possession of controlled substances, complained of difficulty in sleeping, poor impulse control, irritability, and depressed mood. She was given oral quetiapine 600 mg/day. On one occasion, she crushed two 300-mg tablets, dissolved them in water, boiled them, drew the solution through a cotton swab, and injected the solution intravenously. Apart from having the best sleep I ever had she described no dysphoric, euphoric, or other effects. She admitted to previous intranasal abuse of crushed quetiapine tablets. 

Intramuscular Rapid if an aqueous solution less rapid if depot forms Moderate volumes lipid vehicles irritant drugs Inadvertent intravenous injection pain or necrosis at injection site... 

Intravenous formulations are probably the least demanding of all injectates the human vein is quite robust, although venous irritancy is often encountered in clinical trials. A surprising example of this robustness is seen when inducing anesthesia with thiopental sodium (sodium thiopentone). The upper limb veins tolerate these alkaline solutions with impunity, but the solutions are very damaging when administered occasionally and iatrogenically into the cubital fossa a solution at pH 9 can cause serious injury to the structures at the elbow, including the median nerve. 

If a 1 % solution is injected intravenously into rabbits at the rate of 1 cc. in 18 sec., the toxicity is about twice that of cocaine. By subcutaneous injection the toxicity appeared to be about five times cocaine. A 2% solution applied to a rabbit s cornea did not produce complete anesthesia. Moreover, the solution appeared to be distinctly more irritating than a similar solution of cocaine hydrochloride although it was only faintly acid in reaction. There was no sign of dilation of the pupil as is noticed with cocaine hydrochloride. 

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