Table 3.

Suspected drug classes involved in adverse drug reactions, according to the Anatomical Therapeutic Chemical–World Health Organization (WHO–ATC).

Thiesen et al.19
ATC level	WHO–ATC	n	n/3022 (%)
Anesthetics	N01	957	31.67
Analgesics	N02	707	23.40
Antineoplastic agents	L01	384	12.71
Antibacterials for systemic use	J01	307	10.16
Cough and cold preparations*	R05	144	4.77
Corticosteroids for systemic use	H02	61	2.02
Drugs for obstructive airway diseases	R03	58	1.92
Antiemetics and antinauseants	A04	51	1.69
Psycholeptics	N05	42	1.39
Diuretics	C03	41	1.36
Others	–	270	8.93
Silva et al.20
ATC level	WHO–ATC	n	n/165 (%)
Antibacterials for systemic use	J01	41	24.85
Diuretics	C03	24	14.55
Antiepileptics	N03	23	13.94
Analgesics	N02	17$	10.30
Corticosteroids for systemic use	H02	18	10.91
Antihypertensives	C02	9	5.45
Drugs for obstructive airway diseases	R03	8	4.85
Drugs for acid-related disorders	A02	3	1.82
Immunosuppressants	L04	4	2.42
Cardiac therapy	C01	5	3.03
Others	–	18	10.91

^*This item corresponds only to codeine, classified by the WHO–ATC as ‘cough and cold preparations’, but classified as an analgesic by the study.

^$Sum of analgesics and sedatives, according to the authors.