Istin

What is Istin?

Istin is a type of medicine called a calcium channel blocker used to treat high blood pressure. It helps to keep your blood pressure under control in the long term and prevents a heart attack or stroke from occurring in the future. Also known as Amlodipine, it can be used to help treat angina and the chest pain associated with it too.

How does Istin work?

Istin works by relaxing the blood vessels, allowing them to widen so that blood can flow more freely around the body, lowering the blood pressure. It helps angina by widening the arteries so that the heart receives an adequate blood and oxygen supply. This prevents chest pain from occurring. 

How long does Istin take to work?

Istin will begin to work on the first day you start taking the medication. High blood pressure often does not produce symptoms so taking Istin may not make you feel any different. This does not mean the medicine isn't working so it's important to keep taking it. For angina, Istin will take a couple of weeks to take effect and you should feel a reduction in your chest pain after this time period. 

Active ingredients

Amlodipine is the active ingredient within Istin. 

Inactive ingredients

The other ingredients are: dibasic calcium phosphate, magnesium stearate, microcrystalline cellulose and sodium starch glycollate.

How to start taking Istin

Always follow the instructions given by your doctor or pharmacist on how to take Istin as the dosage will vary depending on why you are taking it. You can take Istin at any time of the day but it's best to stick to the same time each day. The tablets should be swallowed with a glass of water and can be taken with or without food. A liquid version can be prescribed if you have trouble swallowing pills. Always measure out the liquid correctly using the plastic measuring spoon provided as a teaspoon or tablespoon is not accurate. 

Istin dosage

The standard dose of Istin is 5mg per day which can be increased up to 10mg depending on the severity of your symptoms. 

Istin side effects

Common side effects include: 

• Headaches
• Dizziness
• Tiredness
• Flushing 
• Double vision
• Heart palpitations
• Shortness of breath
• Nausea 
• Abdominal pain
• Indigestion 
• Constipation
• Diarrhea
• Swollen ankles 

Less common side effects may include:

• Changes in mood
• Insomnia
• Vomiting
• Dry mouth
• Tremors 
• Taste disturbances 
• Pins and needles 
• Numbness or pain in the joints or muscles
• Tinnitus 
• Erectile dysfunction 
• Gynaecomastia
• Skin rash or itching 
• Frequent urination 
• Hair loss
• Low blood pressure
• Chest pain
• Arrhythmias
• Weakness 
• Fainting 
• Changes to weight
• Coughing 

Rare side effects may include: 

• Jaundice
• Hepatitis 
• Pancreatitis 
• Gastritis 
• Gingival hyperplasia
• Peripheral neuropathy
• Reduced number of white blood cells 
• Vasculitis 
• Hyperglycaemia
• Heart attack
• Allergic reaction   

Contraindications

Istin should not be taken if: 

• You are allergic to amlodipine or any of the ingredients in the medicine 
• You are pregnant or trying to get pregnant 
• You are breastfeeding 
• You have liver or kidney disease 
• You have heart failure 
• You have experienced a heart attack recently

Drug interactions

The following medicines can interfere with Istin: 

• Clarithromycin 
• Erythromycin 
• Rifampicin 
• Other types of high blood pressure medications
• Itraconazole
• Ketoconazole
• HIV medicines 
• Hepatitis C medicines 
• Carbamazepine
• Phenytoin
• Phenobarbital
• Primidone
• Medication which suppresses your immune system 
• A dose exceeding 20mg a day of Simvastatin
• St John's Wort 

You should also avoid drinking too much grapefruit juice while you are taking Istin as it interacts with the way the medication works. 

How to cope with Istin side effects

You may experience headaches in the first week of taking Istin. These should disappear but staying hydrated and using painkillers will help. If you feel dizzy or experience a pounding heartbeat after taking it, sit or lie down until the symptoms ease off. Try to take it at times where you are able to sit down and rest. Reducing your caffeine, alcohol and smoking intake can help to ease a pounding heartbeat, as can eating smaller meals. Sitting with your legs raised will ease swollen ankles and staying cool and avoiding hot caffeinated drinks should reduce facial flushing.  

Istin and pregnancy

Istin is not suitable for pregnant or breastfeeding women. If you are pregnant, or planning a family, then discuss this with your doctor who will be able to prescribe a medication to treat high blood pressure that is safe for you to use. 

Will Istin affect my fertility?

Taking Istin will not have an effect on your fertility. However, there is a possibility that calcium blockers like Istin may alter sperm and cause difficulty fathering a child using IVF. 

Lifestyle changes to make when taking Istin

There are many positive changes you can make alongside your Istin medication to help improve your blood pressure and maintain good health. Eating a healthy diet that's low in salt and saturated fats, stopping smoking, cutting down on alcohol and keeping active are some major examples. If you are overweight, a good diet and exercise can help you to reach a healthier weight, another factor which can help high blood pressure. 

Istin vs Amlodipine

Amlodipine is the generic version of the medicine. Istin is a branded version of Amlodipine. 

Istin vs other ACE inhibitors

Istin is a calcium channel blocker which works slightly differently to ACE inhibitors. Both are effective in treating high blood pressure but there are several factors which will determine which type of medicine is most suitable for you. ACE inhibitors are more likely to be prescribed to patients under the age of 55. People with an African or Caribbean origin and those over 55 will be prescribed a calcium channel blocker in the first instance. 

Istin vs other high blood pressure medication

There are lots of factors which influence which type of high blood pressure medication is best for you. These include age, ethnicity, medical history and any other medical conditions you may have. Istin is a calcium-channel blocker and the other types of medication available for high blood pressure include ACE inhibitors, Angiotension receptor blockers, beta blockers and  diuretics. 

Will I need to take Istin forever?

It's likely that you will need to take Istin for life as this is a long term treatment for managing high blood pressure and preventing a heart attack or stroke in the future. 

Is long term use of Istin safe?

Istin is designed for long term use so it is safe to take it in this manner. It's important to keep taking your medication, unless your doctor tells you otherwise, even if you feel well otherwise your blood pressure is likely to rise again. 

Can I stop taking Istin if my blood pressure is lower?

When your blood pressure lowers and reaches a normal level, you should continue to take your Istin medication. Stopping the medicine may reverse the effects of it and result in your blood pressure going up again. As a general rule, you should keep taking Istin unless you are told by your doctor to stop. 

Can I stop taking Istin if I change my lifestyle?

Istin combined with a healthy lifestyle is the best thing you can do for high blood pressure. While you are taking Istin, your doctor will regularly monitor your blood pressure to find out how well the medicine is working. Most people will take Istin for life but your doctor will assess your condition and individual health to determine what is most suitable for you. 

Is Istin addictive?

Istin is not addictive. 

Can I take Istin before surgery?

You can continue to take Istin as usual before surgery. If you are taking other types of medication for high blood pressure like ACE inhibitors and Angiotensin Receptor Blockers then you should stop taking these 24 hours before you are due to have surgery. 

Sources

• NHS > Amlodipine
• Blood Pressure UK > Medicine Types
• Blood Pressure UK > Choosing Meds