O

Obesity, 585
antihypertensive therapy, 414
diabetes mellitus type 2, 585
Observational cohort studies, 51–52
Observational studies, adverse drug reactions, 112
Observed minus expected, meta-analyses, 49
Obsessive-compulsive disorder (OCD), 335
treatment, 332t, 335
Obstetric anaesthesia, 307–308
Octapla (solvent–detergent virally inactivated fresh frozen plasma), 484
Octreotide, 597
portal pressure therapy, 549
secretory diarrhoea, 538
Oculomucocutaneous syndrome, 407–408
Odds ratio, meta-analyses, 49
Oedema, 456
Oesophageal band ligation, acute variceal haemorrhage, 549
Oesophageal cancer, tobacco smoking, 151
Oesophageal dysmotility, management, 532–533
Oesophageal variceal bleeding, β-adrenoceptor-blocking drugs, 406
Oesophageal varices, bleeding, 599
Oesophagitis, 528
eosinophilic, 532
Oesophagus, 528
drug effects, 530
Oestrogen–progestogen therapy, 623
Oestrogen replacement therapy, 119
Oestrogens, 603–604
administration routes, 603
choice of, 603
conjugated, 603
formulations, 603
indications, 603
micturition, 464 see also specific types
Official name, 69
Off-label use, 66
Ofloxacin, 188
tuberculosis therapy, 209
Oil-based lubricants, 610
Oil-in-water creams, 261
Ointments, 261–262
Olanzapine
administration routes, 324
adverse reactions, 326t
Olmesartan, 400
Olsalazine, 541
Omega-3 marine triglycerides (Maxepa), 450
Omeprazole, 530
Onchocerca volvulus, 237t
Onchocerciasis, 237t
Onychomycoses, 269t
Open trials, 46
Opioid(s), 283–285
agonist drugs, 285–287
antagonists, 288
bioavailability, 285t
cardiovascular system effects, 284
choice of, 288, 288t, 289t
classification, 283, 283t
CNS effects, 284
cough, 468
dependence treatment, 140
dependency, 289
gastrointestinal tract effects, 284
mixed agonist-antagonists, 287
mode of action, 283
multiple system actions, 287–288
partial agonists, 287
pharmacodynamics, 283
pharmacokinetics, 284–285
poisoning, 123
receptors, 283
regional anaesthesia, 306
route of administration, 285
systemic effects, 284
tolerance, 78, 289
urogenital tract, 284
Opioid addiction, 289
pain relief, 289
Opportunistic infections
antimicrobial chemoprophylaxis, 167
antimicrobial-induced, 171
cytotoxic drugs, 514
HIV infection, 216 see also specific infections
Opportunity cost, pharmacoeconomics, 25
Oral adsorbents, poisoning therapy, 125
Oral antidiabetic drugs, 578–582
diabetes mellitus type 2, 580–581
glucose absorption reduction, 580
insulin secretagogues, 578–579
insulin sensitizers, 579–580 see also specific drugs
Oral combined contraceptive, 607–609
benefits, 608
choice of, 609
contraindications, 608
duration of use, 608
formulations, 609
problems, 609
Oral contraceptives
antiepilepsy drugs, 353
drug interactions
anaesthesia, 308
diabetes drugs, 581
Oral formulation, oestrogens, 603
Oral preparations
androgens, 601
antimicrobial drugs, 166
iron chelators, 500
iron preparations, 498, 498t
Oral rehydration salts (ORSs), 537
Oral rehydration therapy (ORT), 537
Orchidectomy, 518
Order of reaction See Pharmacokinetics
Organic nitrates
angina pectoris, 411
vasodilators, 394–395
Organic salts, 540
Organism of the Rational Art of Healing (Hahnemann), 16
Organophosphorus pesticide poisoning, 132
Oritavancin, 180
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Orlistat, 585
hyperlipidaemia treatment, 450
Orphan drugs, 36
Orthostatic hypotension, chronic, 391–392
Oseltamivir (Tamiflu), 220–221
Osmosis, drug mechanisms, 75
Osmotic diarrhoea, 536
Osmotic diuretic drugs, 459
efficacy, 455
proximal convoluted tubules, 452–453, 453f
Osmotic laxatives, 540
Osteoarthritis, 255
Osteomalacia, 624
Osteoporosis, 619, 622–623, 622f
adrenal steroid effects, 564
cannabis, 156
corticosteroid-induced, 623
heparin adverse effects, 489
Otitis media, 192
Ototoxicity, 181
Outcome trials, 65
Overdoses, 122–134
accidental, adrenaline (epinephrine), 387
acute, aspirin (acetylsalicylic acid), 247
benzodiazepines, 341
digoxin, 436
incidence, 122
lithium, 330
monoamine oxidase inhibitors, 321
paracetamol, 122
phenytoin, 357 See also Poisoning
Over-the-counter medications, monoamine oxidase inhibitor interactions, 320
22-Oxacalcitriol, 619
Oxazepam, 340t
Oxcarbazepine
anti-epileptic effects, 356
dosages, 355t
Oxprenolol, 405t
Oxybutynin, 381
micturition, 464
Oxycodone, 286
analgesic equivalent, 289t
bioavailability, 285t
relative potency, 288t
Oxygen–nitrous oxide See Entonox
Oxygen therapy, 470
acute severe asthma, 477
as antidote, 128t
carbon monoxide poisoning, 131
chronic obstructive pulmonary disease, 479
cytotoxic drugs, 517
high-concentration, 470
inhalational anaesthesia, 300
poisoning resuscitation, 123–124
Oxytocics, 612
Oxytocin (Syntometrine), 612
labour induction, 613
synthetic, 612
uterine haemorrhage, 613