Codeine is a Isoquinoline alkaloid
Codeine is metabolized in the body to morphine but is far less
habit forming than morphine and only a very small portion of the codeine is
converted. Codeine is an effective analgesic but only in small doses. If the
dosage is increased it increases the side effects without any significant
increase in the therapeutic effect of the drug.
Codeine is antitussive, analgesic and narcotic.
Side effects of codeine can be nausea, constipation, drowsiness and urinary retention. Overdose can cause respiratory failure and death.
Isoquinoline Alkaloids: A large class of medically active alkaloids with very varied properties although this group does contain many constituents from which the most habit forming drugs are made. Precursors of isoquinoline alkaloids are tyrosine and phenylalanine.
Properties of these alkaloids range widely from Anti-inflammatory, antifungal, antitumor, antimicrobial and antiviral to analgesic, narcotic and antitussive, plus virtually everything in-between. Because of this very wide scope each of the alkaloids should be regarded as individual and no general properties can be attributed to the group known as isoquinoline alkaloids.