- Aspirin – Aspirin has been around for hundreds of years and has been used as an antipyretic analgesic, and more recently, an anti-thrombotic agent in the circulation of a variety of cells and cell components, one of which are called platelets, and these are directly responsible for initiation of blood clots in arteries. Aspirin inhibits the activation of the platelets, making them less sticky and stops them initiating the cascade of blood clotting in the artery.
- Clopidogrel – Clopidogrel has an action similar to Aspirin, but is complimentary to Aspirin and is used for long-term maintenance of patient’s following stents, heart attack or stroke. It has a number of potential problems in that not every patient is equally responsive to Clopidogrel and some patients may be resistant to it and gain no benefit. It is usually co-administered with Aspirin prior to and following stent implantation.
- Ticagrelor – Ticagrelor again is a compliment to Aspirin. It shows much lower individual variability between patients and is very powerful in inhibiting platelet activation and protecting patients from blood clots. It is used extensively in patients with unstable cardiac syndrome such as unstable angina or heart attacks.
- Beta blockers – Beta blockers have been used in the treatment of cardiac disease for over 40 years and the original beta blockers came with a number of problems. These so called “off target” effects cause problems such as cold peripheries, impotence, lethargy, poor concentration. More recent generations of beta blockers, which are very specific for the heart rate, and also may have other chemical components which dilate up blood vessels seem to cause less of these side effects, and the more modern agents used, such as Bisoprolol, Carvedilol and Celiprolol are generally well tolerated. In the management of angina, they are used to slow down the heart rate, decreasing the amount of oxygen required by the heart, and increasing the time in between heart beats for blood to enter the heart muscle. They are the first line of treatment for angina.
- Ivabradine – Ivabradine has a specific effect on the sinus node in the atrium, i.e., the heart zone internal pacemaker. It has very few off target effects and is excellent at slowing the heart rate to give the benefits provided by beta blockers without any of those side effects. It can be used as first line treatment of angina.
- Nitrate compounds such as Isosorbide Mononitrate, Isosorbide dinitrate, Glyceryl trinitrate and Imdur – Nitrates act directly on the smooth muscle inside the arteries and veins in the circulation. They dilate up those arteries and veins allowing improved blood flow and are used either as a sustained release preparation in patient’s with stable angina, or as a tablet or spray under the tongue in patients with intermittent angina symptoms for immediate and practical relief. Side effects include headache and flushing.
- Nicorandil, (Ikorel) – Nicorandil has a specific action on the potassium channel in the heart muscle cell and decreases angina in a similar way to nitrates, but is also purported to have specific cardio protective mechanisms. It is well tolerated in the majority of patients, but approximately 30% of patients will develop quite significant headache during the initiation of treatment, and hence treatment is started at low dose and gradually titrated upwards. Patients experiencing headache in the early phase of treatment may benefit from the use of regular Paracetamol during this phase.
- Ranolazine, (Ranexa) – This is a specific drug which acts on another channel within the heart muscle cell and decreases heart muscle oxygen demand and is a very powerful anti-anginal drug. It may be used early on in the treatment of angina, in combination with beta blocker, or in individuals where, despite stents and other medication, the angina is persistent and refractory. Again, it is started in low dose and gradually titrated upwards at further visits.
- STATINS – The prototype statin in the United Kingdom was Simvastatin and this is still widely used today. Other statins available which can be used at lower doses to achieve equivalent response are Atorvastatin and Rosuvastatin, (Crestor). Statins work in the liver by enhancing the uptake of LDL and its degradation in the liver. With the exception of Crestor, they are best taken on retiring to bed at night when the majority of LDL synthesis takes place. They are extremely safe drugs, and there is irrefutable and extensive evidence from clinical trials carefully conducted in hundreds of thousands of patients, over many years, showing their benefits in individuals with established coronary disease, particularly those who are found to be at high risk with abnormal cholesterol levels. Their role in the primary prevention of coronary disease in individuals with normal coronary arteries is less clear. There is general consensus that their use in asymptomatic individuals, who have had cardiac CT or other imaging to show significant deposits of cholesterol in the arteries, is still well established. Their side effects are noted, occurring in up to 10% of patients, and largely relate to the effects of the statin on large muscle groups with muscle aches and pains being the most frequent side effect, often leading to discontinuation of the drug.