Commonly prescribed drugs are drugs that are frequently provided by doctors in a prescription to treat a certain disease. These drugs are often first-line treatment for the target diseases and are effective in tackling the symptoms. An example of the target disease is ischemic heart disease. Some examples of commonly prescribed drugs for this disease are beta-blockers, calcium-channel blockers and nitrates.
In accordance with the pharmacological effects, commonly prescribed drugs can be divided into different groups. Drugs in the same group exert nearly identical effects, and can be utilized for treating the prevailing disease and sometimes, preventing complications of the existing diseases.
The use of commonly prescribed drugs can be reflected from the number of prescriptions of the drugs. Countries have their own dataset in recording the trend of commonly prescribed drugs. For example, the United States uses the Medical Expenditure Panel Survey (MEPS) and England uses the English Prescribing Dataset to record the prescription data for showing which drugs are commonly prescribed.
Understanding commonly prescribed drugs allows healthcare professionals to react to symptoms quickly and new treatment strategies can be developed. However, the data for commonly prescribed drugs may be outdated due to the time lag between data collection and publication as well as errors in data collection process.
History Commonly prescribed drugs are prescribed according to guidelines around the world. For instance, for ischemic heart disease, the American College of Cardiology/American Heart Association (ACC/AHA) guideline is used in the United States and the European Society of Cardiology (ESC) guideline is used in Europe. Western guidelines are more commonly used for reference during the development of local practice guidelines due to the large number of western guidelines stored in guideline databases. The data of prescriptions are collected through the government, such as Medical Expenditure Panel Survey (MEPS) in America and the Pharmaceutical Benefit Scheme (PBS) in Australia, providing information on the actual prescription volume of drugs.
The United States The Medical Expenditure Panel Survey (MEPS) conducted by the Agency for Healthcare Research and Quality (AHRQ) via the United States government is used to collect prescription data and data for other healthcare services, including home healthcare, children's health and preventive care in America. The survey started in 1996 and was the predecessor of the National Medical Expenditure Survey (NMES) and the National Medical Care Utilization and Expenditure Survey (NMCUES), which were conducted in 1977 (NMES-1), 1980 (NMCUES), and 1987 (NMES-2). The survey is updated every year with the renewed data from the country. The prescription data is published in the Prescribed Medicines File of the MEPS. The collection of data involves two components: Household component and the Medical Provider component. The household component collects self-reported data of the prescribed medicines and the demographic information of the respondents. The Medical Provider component acts as a piece of follow-back information provided by the pharmacy including a computerized printout for all prescription filled for the patient.
The United Kingdom The English Prescribing Dataset (EPD) from the NHS Business Services Authority (NHSBSA) provides prescription data in the United Kingdom. The dataset was created in 2014. EPD is a combination of the Detailed Prescribing Information (DPI) and the Practice Level Prescribing in England (PLP). Both DPI and PLP are previous datasets from NHSBSA and NHS Digital respectively and EPD aims to replace them both in the future, but no specific date of replacement is given. EPD collects data from England, Wales, Scotland, Guernsey, Alderney, Jersey and the Isle of Man. EPD provides the item, quantity, net ingredient cost, actual cost, average daily quantity (ADQ), practice name and address details of the prescription.
Australia The Pharmaceutical Benefits Scheme (PBS) from the Australian Government Department of Health provides the prescription data of prescriptions under PBS. PBS started in 1948 and the under co-payment prescriptions were added into the dataset from 1 April 2012. It publishes the PBS expenditure and prescriptions report every year recording prescription data in the past 12 months. The examples of data it provides are the top 50 drugs by total prescription volume and the top 50 drugs by government cost.
Benefits and limitations
Benefits Understanding commonly prescribed drugs for different diseases can allow healthcare professionals to be more confident and decisive when choosing the most suitable treatment for the patient. This can also help develop new treatment strategies by researchers for more effective treatments. By enriching the knowledge of commonly prescribed drugs, pharmacy students will be more familiar with their mechanism of action, first-line therapy indications and side effects.
Limitations Limitations include time lag for the conducted survey. The Medical Expenditure Panel Survey (MEPS) shows data recorded two years before the publishing of the survey. The time lag may lead to a difference in representing the current prescribing practice with the recorded data in the survey. Questionnaires which are self-reported tend to create recall bias. Respondents are likely to underreport the number of prescription drugs they have as those drugs are usually for short-term use and intermittent use, such as analgesics and topical agents.
Examples of commonly prescribed drugs Two diseases from the top 10 causes of death introduced by the World Health Organization (WHO) in 2019 are used as examples, namely ischemic heart disease (ranked 1st) from cardiovascular diseases and Chronic Obstructive Pulmonary Disease from respiratory diseases (ranked 3rd). Although stroke is ranked 2nd by WHO, drugs used are similar to ischemic heart disease. Moreover, surgical interventions are commonly required, so it will be out of the scope of this article and it will not be introduced.
Ischemic Heart Disease
Ischemic Heart Disease (IHD) or coronary heart disease is the lack of supply of blood to an area in the heart, often due to plaque formation (atherosclerosis), causing inadequacy of oxygen to heart muscle and eventually leading to myocardial infarction. This disease can be classified into acute and chronic coronary heart disease. This disease caused 8.9 million deaths in 2019 and was ranked 1st in the top 10 causes of death globally by the World Health Organization (WHO).
The treatment of Ischemic Heart Disease can be divided into two directions: risk factor control and symptomatic relief.
Commonly prescribed drugs for Ischemic Heart Disease Types of drugCommon ExamplesMechanism of benefit and effectSide effects, caution & contraindicationsRemarksBeta-blockers Metoprolol Atenolol BisoprololBlock beta-1 receptors in the heart → stop the effects of catecholamines on the heart→ reduce heart rate, heart contractility and conduction velocity → reduce the workload of the heartSide effects
Bradycardia Hypotension Heart Block Impaired glucose metabolism Central Nervous System effects: fatigue, depression, insomnia Aim to control heart rate to 55-60 beats per minute at rest Used for symptomatic reliefCaution Reduce the dose gradually over 2–3 weeks when withdrawing to avoid ischemia and myocardial infarctionContraindications Pre-existing bradycardia History of uncontrolled reactive airway disease (asthma) Severe Peripheral Arterial Disease (critical limb ischemia) Unstable HFrEF Diabetes with frequent episodes of hypoglycemiaCalcium Channel Blockers (CCB)Dihydropyridine (DHP) CCB: Amlodipine Felodipine Nifedipine SRBlock L-type calcium channels in arterial smooth muscle cells → reduce vasoconstriction → reduce arterial blood pressureSide effects
Reflex tachycardia Hypotension Headache Gingival hyperplasia Peripheral edemaAvoid intake of food that interacts with CYP3A4, such as grapefruit and pomelo Used for symptomatic reliefContraindications HFrEF (for nifedipine) Obstructive myopathyNon-DHP CCB: Verapamil DiltiazemBlock L-type calcium channels in the myocardium → decrease heart rate and contractilitySide effects Bradycardia Hypotension Heart blockContraindications HFrEF Bradycardia Sick sinus syndromeCaution CCB are CYP3A4 inhibitors, especially non-DHP CCBNitrates Nitroglycerin Isosorbide mononitrate Isosorbide dinitrateMetabolized in body → release nitric oxide → increase cyclic guanosine monophosphate (cGMP) → vasodilating effects predominant on veins and epicardial coronary vessels → decrease preload, myocardial wall tension and increase blood flow to heartSide effects Headache Flushing Nausea Postural hypotension Syncope Sublingual nitroglycerin is used for acute coronary syndrome Isosorbide mononitrate and isosorbide dinitrate are used for symptomatic relief when blood pressure <130/80 mmHg Not to be used as monotherapy in chronic coronary syndromeCaution Avoid concomitant use of PDE-5 inhibitors A nitrate-free period for 10–14 hours every day to prevent nitrate toleranceContraindications Hypertrophic obstructive cardiomyopathyNon-steroidal
anti-inflammatory drugs (NSAID) Aspirin (low dose)Block cyclooxygenase-1→ reduce thromboxane A2 production → reduce platelet activation and aggregation → reduce plaque formation and risk of adverse cardiovascular eventsSide effects Increased bleeding risk, especially in the stomach Gastrointestinal irritation Used in risk factor control and acute coronary syndrome Dual antiplatelet therapy with P2Y12 inhibitors for a reduction of risk of major adverse cardiac events for all acute coronary syndrome patients Concomitant use with proton pump inhibitors is recommended for patients who are at a high risk of gastrointestinal bleeding Use at low dose: 75–100 mg orally once a dayCaution History of gastrointestinal bleedingContraindications Allergy to NSAID/aspirin Patients with triad of asthma, rhinitis and nasal polypsP2Y12 Inhibitors Clopidogrel Prasugrel TicagrelorBlock P2Y12 receptors on platelets → prevent platelet activation by adenosine monophosphate (ADP) → prevent aggregation of platelets and plaque formationSide effects Increased bleeding risk Rash (Clopidogrel) Dual antiplatelet therapy with aspirin for a reduction of risk of major adverse cardiac events for all acute coronary syndrome patientsCaution Metabolism of P2Y12 inhibitors requires CYP450 enzymes → potential drug interactionsContraindications Prasugrel Stroke Older than 75 years old Lighter than 60 kgStatins Atorvastatin Simvastatin Rosuvastatin Pravastatin Inhibit HMG-CoA reductase → reduce cholesterol synthesis Decrease high-sensitivity C-reactive protein Pleiotropic properties: improve endothelial function and reduction of inflammation at coronary plaqueSide effects Muscle weakness Fatigue Rhabdomyolysis Hepatotoxicity Used for risk factor control If the maximum dose of statin cannot achieve the patient's goal, combination with ezetimibe is recommended.Caution Atorvastatin and simvastatin are metabolized by CYP450 enzymes, leading to CYP450 enzymes related potential drug interactionsContraindications Active liver disease Pregnancy or breastfeeding Unexplained persistent increase of liver function test results
Chronic Obstructive Pulmonary Disease (COPD)