last updated 12-10-2021

Drug interactions

Drug interactions

Three kinds of interactions between drugs can occur:

  • Pharmaceutical interactions take place between drugs before administration. For example, a precipitate can be formed when two drugs are mixed in a solution (i.e. phosphates and calcium).
  • Pharmacokinetic interactions take place when one drug alters the kinetics of another drug (ciprofloxacin inhibits the metabolism of coumarins).
  • Pharmacodynamic interactions usually take place at the level of receptors and are thus molecular interactions in a physiological perspective (propranolol inhibits the effectiveness of salbutamol in asthma).
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