When it comes to angina pectoris medicines, one has to mention Istin, a branded tablet drug developed and manufactured by Pfizer pharmaceutical company. Based on amlodipine as an active ingredient, this medicine is classified as calcium-channel blocker (or calcium antagonist). Just one tablet per day in the right dosage prescribed by your doctor is enough to facilitate the flow of blood to the heart and reduce the characteristic chest pain. Also adept at treating hypertension, Istin is commonly prescribed medicine that has helped thousand to manage their angina.

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Angina pectoris: A short overview

Angina pectoris is a medical condition affecting the arteries surrounding the heart. It’s characteristic tell-tale symptoms include recognizable tightness and dull pain in the chest, sometimes spreading to the left arm, neck and the jaw. This pain usually takes form of a so-called angina attack. In cases of stable angina, these attacks will occur in response to common triggers including physical strain and stress, while in unstable angina, attacks are significantly less predictable, often without obvious trigger.

While angina pectoris predominantly affects people aged 55 and over, it can manifest in all people, regardless of their age or sex. According to the most recent statistics regarding UK, roughly one in twelve men and one in thirty women in their late 50s are affected by this condition. But, it is important to note that age isn’t the only contributing factor when it comes to angina – medical experts agree that certain lifestyle choices and habits such as unhealthy diet, smoking, drinking alcohol or lack of physical activity all increase the risk of developing angina.

The characteristic symptoms associated with this condition are brought on by the hardening, narrowing and eventual clogging up of the arteries through which oxygen-rich blood is supplied to the heart. When this part of the cardiovascular system is compromised, the supply of oxygen to the heart will fail to meet muscle’s needs. As a consequence, heart will begin beating faster and harder in order to compensate. While in short term this will solve the lack of oxygen, in the long term, the strain put on heart can cause significant damage and further complications.

Who is at risk of developing angina?

Medical scientists have identified several factors that play an important role in increasing the risk of developing angina. These factors include diabetes, high blood pressure, family history of heart problems and already mentioned lifestyle habits and choices.

Speaking of these habits, it is important to mention that introducing changes to your lifestyle can significantly reduce the risks and serve as an important preventive measure.

Angina pectoris treatment

The exact method of angina treatment will largely depend on the severity of the condition, including whether it is stable or unstable. As a rule of thumb, stable angina can be treated much easier with prescription medicines and some lifestyle changes, while unstable angina will necessitate medical attention, sometimes even in the long term.

Istin in angina treatment

The high success rates of Istin are rooted in the effectiveness of its active ingredient, a pharmaceutical compound called amlodipine. Classified as a calcium antagonist, this substance is highly adept at reducing the provision of calcium to the smooth muscle tissue lining the arterial walls. As a result, the blood vessels will relax and widen, thus contributing to the increase of blood flow to and from heart. Consequently, supply of oxygen to the heart will increase too, allowing it to relax and beat in the usual tempo and without any extra strain.

Can I buy Istin online in the UK?

As many other medical products and treatments, Istin is also available for purchase online. However, as this is a prescription-only medicine, you will still have to provide a valid prescription or, if it is your first time buying this treatment, obtain one from a certified medical professional.

This can be accomplished in two different ways. Traditional route would mean you will make an appointment, visit a doctor, ask for a prescription and then wait in pharmacy to actually buy the medicine. Alternatively, you can rely on one of numerous online clinics in the UK where you can consult with a doctor from the comfort of your own home. Usually, you will use either a live chat app or a customized medical questionnaire which the doctor will use to gain insight into your medical profile and history.

If you are suitable for Istin treatment, the doctor will issue the prescription and use it that very same moment to order the medicine and send it to the address you provided.

How is Istin used?

When using this medicine, it is very important to precisely follow the instructions provided by your prescriber. By doing so, you will simultaneously reduce the risk of side effects and increase the chances of successful treatment. Before you begin using Istin, you should go through official patient information leaflet in order to learn or the relevant details about this medicine.

Here, we will present you with just a couple of main points which will help you get a clearer picture of how Istin treatment will look like.

  • Always use as instructed
  • The beginning dose is usually one 5mg tablet per day
  • In some cases, the doctor may decide to increase the dose to one 10mg tablet daily
  • Take the tablets whole with water
  • Avoid drinking grapefruit juice when using Istin
  • Never exceed the prescribed amount
  • If you miss a dose, just continue with your treatment as usual – never compensate by doubling the next one

For a more detailed instruction, please refer to the official patient information leaflet.

Are there any known Istin side effects?

As is the case with all prescription medicines, Istin has also been known to cause certain side effects in some people who have been using it. While not everyone will experience these adverse effects, it is important to be aware of them in case they do occur so you can contact the emergency services and ask for advice.

You should stop taking Istin and contact the doctor immediately if you notice any symptoms indicative of an allergic reaction:

  • Sudden wheezing
  • Chest pain
  • Breathlessness
  • Swelling of the tongue, eyelids, face or lips
  • Skin reactions such as rash, hives, itching, peeling, blistering or swelling
  • Inflammation of the mucous membranes
  • Abnormal heartbeat
  • Pancreas inflammation (manifested through abdominal and back pain)

If we take into consideration the frequency of occurrence of documented side effects, we could list them in the following manner:

Frequency of occurrence

Side effects

Common (1 in 10 users)

Headache, dizziness, sleepiness, palpitations, flushing, abdominal pain, swelling of the ankles, tiredness

Uncommon (1 in 100 users)

Mood changes, trembling, taste abnormalities, fainting, weakness, reduced sensitivity to pain, itchy skin with red patches, difficulty when urinating

Rare (1 in 1000 users)



Very rare (1 in 10.000 users)

Lowered white blood cell count, hyperglycaemia, liver inflammation, muscle tension, photosensitivity, movement disorders, nerve problems

Keep in mind that this is just a brief summary of side effects – for a more comprehensive list please refer to the official patient information leaflet that is provided within every box of Istin.

Istin contraindications

Naturally, not everybody is suitable for Istin treatment and the doctor might advise against using this medicine in several scenarios.

For example, this might be the case if you are currently taking any of the following medicines:

  • Ketoconazole
  • Itraconazole
  • Ritonavir
  • Indinavir
  • Nelfinavir
  • Rifampicin
  • Erythromycin
  • St John’s wort
  • Diltiazem
  • Verapamil
  • Dantrolene

Alternative, Istin can carry significant risks for people affected by:

  • Obstruction in the heart caused by aortic stenosis
  • Heart failure or heart attack
  • Severe case of low blood pressure
  • Hypersensitivity
  • Liver disease