Drug Subheadings

Drug Subheadings are filters that limit the records retrieved about the drug entered in the Drug name text box to specific aspects, such as adverse drug reaction, drug therapy, drug toxicity, etc. This increases precision when searching these topics. Drug administration routes are special drug subheadings which are searched using the Routes of Drug Administration menu.

To select multiple subheadings, hold down Control key (or Apple key) and select the required subheadings. Multiple subheadings can be searched in an AND or an OR relationship. After selecting two or more subheadings, a default relationship OR will be activated in the radio button below the menu. This can be changed into AND by checking this box. For example, if a drug term is linked to either drug therapy OR adverse drug reaction and the OR relationship is chosen, Embase executes the search as: ‘drug term’/dd_dt OR ‘drug term’/dd_ae. In the same way, if a relationship AND is chosen, the search will be executed as ‘drug term’/dd_dt,dd_ae

The following drug subheadings, here given with their definitions, are available. Unless otherwise indicated, these subheadings are available for records published from 1988.

List of drug subheadings

Drug Subheading Code Definition
Adverse drug reaction dd_ae used for undesired side effects of drugs used at therapeutic dose ranges in humans.
Clinical trial dd_ct used for clinical trials on drugs in humans. See related subheading drug development.
Drug administration dd_ad used when the route of drug administration is a significant aspect of the article. The actual route is indexed using a specific route of drug administration link, introduced in 2000; before 2000, routes were indexed as normal (unlinked) Emtree terms.
Drug analysis dd_an used for the identification, determination or structural analysis of drugs or potential drugs.
Drug combination dd_cb used with drugs that are given in combination, when this is a significant aspect of the article. Indexed as drug mixture before 1988.
Drug comparison dd_cm used when two or more drugs are compared.
Drug concentration dd_cr used for articles providing information on the concentration of drugs in body fluids or tissues.
Drug development dd_dv used for the stages of drug development from screening, isolation and synthesis up to testing in animals, but excluding trials in humans. (See related subheading clinical trial.)
Drug dose dd_do used when drug dosage, including the relation between dosage and effects over time, is a significant factor.
Drug interaction dd_it used for interactions between drugs, or between a drug and food, alcohol or other chemicals in humans or animals.
Drug therapy dd_dt used for both clinical and animal studies on the treatment of diseases and other conditions with drugs; includes curative, palliative, symptomatic and prophylactic treatment.
Drug toxicity dd_to used for toxicity of drugs or other chemicals in animals (incl. LD50 tests), in animal or human cells/tissues, and in other toxicity studies. Used for humans only at non-therapeutic dose ranges, or when lasting damage is caused at therapeutic dose ranges.
Endogenous compound dd_ec used for substances endogenous to the organisms, tissues, cells or body fluids being studied. Introduced in 1991.
Pharmaceutics dd_pr used for drug formulation, including the physical and chemical properties of drugs relevant to drug pharmacy, and the formulation of drug mixtures. Introduced in 1991.
Pharmacoeconomics dd_pe used for the economic evaluation of drug therapy, including cost analysis, treatment outcome and quality of life studies. See related disease subheading disease management. Introduced in 1997.
Pharmacokinetics dd_pk used for kinetics of drug absorption, distribution, biotransformation or elimination in humans and animals.
Pharmacology dd_pd used for the actions and mechanisms of drugs, including drug binding to receptors and studies of drug sensitivity or resistance. Also indexed as pharmacodynamics before 1988.