Respiratory, Gastrointestinal, and Genitourinary Drugs in the Top 300 Prescription Drugs

Based on the Top 300 Prescription Drugs of 2017 (dispensed in 2014), 17 of the therapeutic agents (Table 1) are indicated for the treatment of respiratory abnormalities and represent nearly 185 million prescriptions; 13 of the drugs (Table 2) are indicated for the treatment of GI conditions and represent over 160 million prescriptions; and 8 of the drugs (Table 3) are indicated for the treatment of GU dysfunction and represent nearly 393 million prescriptions.2

Table 1. Respiratory Drugs in the Top 300 Prescription Drugs of 2017.2
Drug* Mechanisms of Action* Indication*
Fluticasone (nasal spray) Synthetic trifluorinated corticosteroid with anti-inflammatory activity Allergic rhinitis
Cetirizine
Loratadine
Selective histaminergic H1-receptor antagonists Allergic rhinitis
Albuterol (inhaler)
Levalbuteral inhaler)
Selective short-acting beta2-adrenergic receptor agonists Bronchospasm with reversible obstructive airway disease
Montelukast Cysteinyl leukotriene (CysLT)-receptor antagonist Allergic rhinitis
Asthma
Exercise-induced bronchoconstriction
Budesonide (inhaler)
Beclomethasone (inhaler)
Anti-inflammatory corticosteroid that exhibits potent glucocorticoid activity Asthma
Mometasone w/formoterol (inhaler) Mometasone furoate is a corticosteroid demonstrating potent anti‑inflammatory activity;
Formoterol is a long‑acting, selective beta2‑adrenergic agonist
Asthma
Fluticasone w/salmeterol (inhaler) Fluticasone is a synthetic trifluorinated corticosteroid with anti‑inflammatory activity;
Salmeterol is a long‑acting, selective beta2‑adremergic agonist
Asthma
COPD
Budesonide w/formoterol (inhaler) Budesonide is an anti‑inflammatory corticosteroid that exhibits potent glucocorticoid activity;
Formoterol is a long‑acting, selective beta2‑adrenergic agonist
Asthma
COPD (including chronic bronchitis and/or emphysema)
Tiotropium
Ipratropium
Long-acting, muscarinic M3‑receptor antagonist Long‑term, once-daily, maintenance treatment of bronchospasm associated with COPD, including chronic bronchitis and emphysema
Albuterol w/ipratropium (inhaler) Albuterol is a selective, short‑acting beta2‑adrenergic receptor agonist;
Ipratropium is a long‑acting, muscarinic M3‑receptor antagonist
Bronchospasm associated with COPD in patients requiring more than one bronchodilator
Benzonatate Anesthetizes the stretch receptors located in the respiratory passages, lungs, and pleura thereby reducing the cough reflex at its source Symptomatic relief of cough
Guaifenesin An expectorant that promotes or facilitates the removal of secretions from the respiratory tract by increasing sputum volume and making sputum less viscous To loosen phlegm (mucus) and thin bronchial secretion, to drain bronchial tubes, and to make coughs more productive
Guaifenesin w/codeine phosphate Guaifenesin is an expectorant that promotes or facilitates the removal of secretions from the respiratory tract by increasing sputum volume and making sputum less viscous;
Codeine, an opioid‑receptor agonist that elevates the threshold for cough
To temporarily control cough due to minor throat and bronchial irritation as may occur with the common cold or inhaled irritants
*FDA-approved information on specific agents is available at DailyMed - the website is a user-friendly, look-up-and-download resource that provides comprehensive, up-to-date information on individual drugs.3
Table 2. Gastrointestinal Drugs in the Top 300 Prescription Drugs of 2017.2
Drug* Mechanisms of Action* Indication*
Omeprazole
Pantoprazole
Esomeprazole
Lansoprazole
Dexlansoprazole
Proton pump inhibition - suppress the final step in gastric acid production by covalently binding to the (H+, K+)‑ATPase enzyme system at the secretory surface of gastric parietal cells Peptic ulcer disease (PUP)
   Active duodenal ulcer
   Active gastric ulcer
Symptomatic gastroesophageal reflux disease (GERD)
Erosive esophagitis (EE) due to acid-mediated GERD
Pathological hypersecretory of H+ (e.g., Zollinger-Ellison syndrome)
Risk reduction of NSAID-associated gastric ulcer
Ranitidine
Famotidine
Reversibly inhibit the action of histamine a histaminergic H2‑receptors on gastric cells
Sucralfate Accelerate healing of ulcer by forming a complex with proteinaceous exudate at the ulcer site and inhibits pepsin activity Short‑term treatment of duodenal ulcers
Docusate
Polyethylene glycol 3350
Osmotic agents – soften stool by increasing the amount of water the stool absorbs in the gut, making the stool softer and easier to pass. To relieve occasional constipation
Meclizine Blocks the vasodepressor response to histamine by histaminergic H1‑receptor antagonism Nausea
Vomiting
Motion sickness
Vertigo
Dicyclomine Potent anticholinergic effect – relieves smooth muscle spasm in the GI tract Irritable bowel syndrome
Metoclopramide Sensitize tissues to the action of acetylcholine – stimulates motility of the upper gastrointestinal tract GERD
Acute and recurrent diabetic gastroparesis
*FDA-approved information on specific agents is available at DailyMed - the website is a user-friendly, look-up-and-download resource that provides comprehensive, up-to-date information on individual drugs.3
Table 3. Genitourinary Drugs in the Top 300 Prescription Drugs of 2017.2
Drug* Mechanisms of Action* Indication*
Tamsulosin
Terazosin
Selective prostate alpha1‑adrenegic receptor antagonism Benign prostate hypertrophy (BPH)
Finasteride
Dutasteride
Inhibit Type II 5α‑reductase that metabolizes testosterone to 5α‑dihydrotestosterone (DHT) in the prostate-reduce androgenic effects BPH
Sildenafil
Tadalafil
Enhance the effect of NO by inhibiting phosphodiesterase type 5 (PDE5), which is responsible for degradation of cGMP resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum BPH
Erectile dysfunction (ED)
Solifenacin
Tolterodine
Muscarinic M1 and M3 receptor antagonism – reduce detrusor over-activity Overactive bladder with symptoms of urinary incontinence, urgency, and increased urinary frequency
*FDA-approved information on specific agents is available at DailyMed - the website is a user-friendly, look-up-and-download resource that provides comprehensive, up-to-date information on individual drugs.3