Effects of oral propranolol in normal subjectsM M LeWinter et al. Clin Pharmacol Ther. 1975 Jun. Show
AbstractThe effects of oral propranolol were evaluated in 10 normal volunteers. The resting heart rate decreased from the mean control value of 68 plus or minus 3.3 (SE) to 56 plus or minus 2.8 beats per minute (bpm) on propranolol (p smaller than 0.001, paired test). Mean systolic blood pressur also decreased from 125 plus or minus 5.0 to 114 plus or minus 4.2 mm Hg (p smaller than 0.03). Resting systolic time intervals were unaffected by propranolol. Mean maximal treadmill exercise tolerance time was not significantly altered by propranolol although the mean heart rate systolic blood pressure product a maximal exertion was markedly decreased (1.91 plus or minus 0.17 vs 2.62 plus or minus 0.17 times 10-4, p smaller than 0.004) . The nonsignificant effect of oral propranolol on resting systolic time intervals and maximum exercise tolerance despite significant changes in heart rate and blood pressure at rest and duringexercise stand in contrast to the reported effects of intravenous propranolol. Explantations for this difference between the effects of oral and intravenous propranolol in normal subjects are examined. Similar articles
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Publication typesMeSH termsSubstancesPropranolol belongs to a group of medicines called beta blockers. It's used to treat heart problems, help with anxiety and prevent migraines. If you have a heart
problem, you can take propranolol to: Propranolol can help reduce your symptoms if you have too much thyroid hormone in your body (thyrotoxicosis). You'll usually
take it together with medicines to treat an overactive thyroid. This medicine is only available on prescription. It comes as tablets, slow release capsules, or as a liquid that you swallow. 3. Who can and cannot take propranololMost adults and children aged 12 and over can take propranolol. But it is not officially approved for treating high blood pressure in children under 12 years old. Propranolol is not suitable for everyone. To make sure it's safe for you, tell your doctor before starting to take propranolol if you:
4. How and when to take propranololPropranolol comes as 2 different types of medicine:
If you are taking it once a day, your doctor may advise you to take your first dose before bedtime, because it can make you feel dizzy. After the first dose, if you do not feel dizzy, take propranolol in the morning. Important: ImportantKeep taking propranolol even if you feel well. You will still be getting the benefits of the medicine. Dosage and strengthPropranolol tablets come in strengths of 10mg, 40mg, 80mg or 160mg. The slow release capsules are 80mg or 160mg. The liquid comes in strengths of 5mg, 10mg, 40mg or 50mg in 5ml. How much you take depends on why you need propranolol. The usual doses for adults are:
Doses are usually lower for people aged over 65 or people with a kidney or liver problem. If your child needs propranolol, your doctor will usually use your child's weight to work out the right dose. How to take itPropranolol does not usually upset your stomach so you can take it with or without food. It's best to do the same each day. Swallow the tablets whole with a drink of water. If you find the tablets difficult to swallow, some brands have a score line to help you break the tablet in half. Check the information leaflet for your brand to see if you can do this. If you're taking capsules, swallow them whole with a drink of water. Do not break, chew or crush them. If you're taking propranolol as a liquid, it will come with a plastic syringe or spoon to help you measure out the right dose. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount of medicine. If you forget to take itIf you forget to take a dose of propranolol, take it as soon as you remember, unless it's nearly time for your next dose. In this case, just leave out the missed dose and take your next dose at the usual time. Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one. If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine. If you take too muchAn overdose of propranolol can slow down your heart rate and make it difficult to breathe. It can also cause dizziness and trembling. The amount of propranolol that can lead to an overdose varies from person to person. Urgent advice: Contact 111 for advice now if:
Call 111 or go to 111 online If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance. Take the propranolol packet or leaflet inside it plus any remaining medicine with you. 5. Side effectsLike all medicines, propranolol can cause side effects in some people, but many people have no side effects or only minor ones. Side effects often improve as your body gets used to the medicine. Common side effectsThese common side effects happen in more than 1 in 100 people. They're usually mild and short-lived. Talk to your doctor or pharmacist if the side effects bother you or last more than a few days:
Serious side effectsIt happens rarely, but some people have serious side effects when taking propranolol. Tell a doctor or contact 111 straight away if:
Go to 111.nhs.uk or call 111. Immediate action required: Call 999 or go to A&E now if:
Serious allergic reactionIn rare cases, propranolol may cause a serious allergic reaction (anaphylaxis). Immediate action required: Call 999 or go to A&E now if:
You could be having a serious allergic reaction and may need immediate treatment in hospital. These are not all the side effects of propranolol. For a full list, see the leaflet inside your medicine packet. Information: You can report any suspected side effect using the Yellow Card safety scheme. Visit Yellow Card for further information. 6. How to cope with side effects of propranololWhat to do about:
7. Pregnancy and breastfeedingPropranolol and pregnancyPropranolol is not thought to be harmful during pregnancy, but it may affect your baby's growth in later pregnancy. Discuss taking propranolol with your doctor or midwife as you may need extra scans to check your baby's growth. If you're trying to get pregnant or you're already pregnant, talk to your doctor about the benefits and possible harms of taking propranolol. There may be other medicines that are better to use during pregnancy. Propranolol and breastfeedingIf your doctor or health visitor says that your baby is healthy, it's OK to take propranolol while breastfeeding. Propranolol passes into breast milk in tiny amounts. It has not been known to cause any side effects in breastfed babies. It's important to treat your high blood pressure to keep you well. Breastfeeding will also benefit both you and your baby. If you notice that your baby is not feeding as well as usual, or seems unusually sleepy, or if you have any other concerns about your baby, then talk to your doctor or health visitor. Non-urgent advice: Tell your doctor if you're:
For more information about how propranolol can affect you and your baby during pregnancy, visit the Best Use of Medicines in Pregnancy (BUMPS) website. 8. Cautions with other medicinesThere are some medicines that may affect the way propranolol works. Tell your doctor if you're taking:
Mixing propranolol with herbal remedies or supplementsThere's very little information about taking herbal remedies and supplements with propranolol. They are not tested in the same way as pharmacy and prescription medicines. Medicine safetyTell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements. 9. Common questions about propranololHow does propranolol work? Propranolol is a type of medicine called a beta blocker. Like other beta blockers, propranolol works by changing the way your body responds to some nerve impulses, including in the heart. It slows down your heart rate and makes it easier for your heart to pump blood around your body. It works differently if you're using it for anxiety. When you are anxious, your brain makes chemical messengers called adrenaline and noradrenaline. These make your heart rate faster and make you sweat or shake. Propranolol helps block the effects of these chemical messengers. This reduces the physical signs of anxiety. It's not fully understood how propranolol prevents migraines. It may work by relaxing the blood vessels involved, or by reducing activity in the visual cortex. This is the part of the brain where migraines are believed to start. How long does propranolol take to work? Propranolol usually starts to work in a few hours. For heart conditions or high blood pressure, propranolol can take up to a week to reach its full effect. You may not feel any different but that does not mean it is not working. It's important to keep taking your medicine. For migraines, it can take several weeks for propranolol to start making a real difference, so keep taking it. How long will I take it for? This depends on why you're taking propranolol. For heart conditions or high blood pressure, treatment is usually long term and may be for the rest of your life. For anxiety, you'll usually take propranolol for a short amount of time, to help with your physical symptoms. Speak to your doctor about the risks and benefits of taking it for more than a few months. This will depend on your symptoms, whether it's a one-off or a recurring problem, how well propranolol works for you and whether you get side effects. For migraines, treatment can last for several months or years, depending on how bad your symptoms are. Can I take propranolol for a long time? Propranolol is generally safe to take for a long time. If you're taking it for a heart condition, or to prevent migraines, it works best when you take it long term. If you're taking it for anxiety, there do not seem to be any lasting harmful effects if you take it for several months or years. But it's best to take propranolol only for as long as you need it. You'll need to have your blood pressure checked regularly if you're taking propranolol for a long time for migraines or anxiety. What will happen if I stop taking it? Talk to your doctor if you want to stop taking propranolol. If you're bothered by side effects, your doctor may be able to prescribe a different medicine instead. Stopping propranolol suddenly may make your health problem worse. In addition, if you stop suddenly after taking it for a long time, you may get extra side effects as a reaction to stopping it. These include an irregular heart rate, sweating and shaking. If you stop taking propranolol, it will take about 1 to 2 days for it to be completely out of your body but the side effects can last for up to 1 week. How does propranolol compare with other heart medicines? Propranolol works as well as other beta blockers for reducing blood pressure. The main difference between propranolol and other beta blockers is that it does not just affect your heart. It can affect other parts of your body too, such as your lungs. There are lots of other medicines to lower your blood pressure and treat chest pain. They work in a different way to beta blockers and include:
Beta blockers are not usually the first choice for high blood pressure. The medicine your doctor prescribes depends on your age and ethnicity. If you're under 55 and not of African Caribbean or black African origin, you'll usually be offered an ACE inhibitor or an angiotensin receptor blocker. If you're 55 or older, or you're any age and of African Caribbean or black African origin, you'll usually be offered a calcium channel blocker. Sometimes you may have to try other blood pressure-lowering medicines if you get side effects. Many people need to take a combination of different medicines to lower their blood pressure. How does it compare with other medicines for preventing migraine? Atenolol, metoprolol, timolol and nadolol are all beta blockers and they work well in preventing migraines. However, most doctors prescribe propranolol. There are some other medicines that are known to prevent migraines but they are not officially approved in the UK. They include amitriptyline, sodium valproate and gabapentin and they may have different side effects. Topiramate can also be used to prevent migraines. It works just as well as propranolol. However, topiramate has not been officially approved for migraine for children under the age of 16. Ask your doctor or pharmacist which medicine is best for you. How does it compare with other medicines for anxiety? Propranolol treats the physical symptoms of anxiety – for example, it stops your heart beating too fast. You'll usually only take propranolol for a short time. The physical symptoms of anxiety are caused by chemical imbalances in the brain. Your doctor may prescribe an antidepressant like sertraline to treat these imbalances. You usually take antidepressants long term. Many doctors prefer medicine-free treatments for anxiety. These include talking therapies like cognitive behavioural therapy. If you're having talking therapy, your doctor may prescribe propranolol at the same time. This will help you with your physical symptoms. Will I need to stop taking propranolol before surgery? Tell your doctor that you're taking propranolol if you're going to be put to sleep using general anaesthetic, or you're having any kind of major operation. Your doctor may advise you to stop taking propranolol before surgery. This is because propranolol can lower your blood pressure too much when it's combined with some anaesthetics. Can I drink alcohol with it? Drinking alcohol can increase the blood pressure-lowering effect of propranolol, which can make you feel dizzy or lightheaded. During the first few days of taking propranolol or after an increase in your dose, it's best to stop drinking alcohol until you see how the medicine affects you. If you find propranolol makes you feel dizzy it's best to stop drinking alcohol. Is there any food or drink I need to avoid? Apart from being careful with alcohol, you can eat and drink normally while taking propranolol. Eating a healthy, balanced diet can help if you have high blood pressure or another heart condition. Will it make me put on weight? Some people on propranolol say they put on weight, especially in the first few months of taking it. This is not known to be a common side effect of taking propranolol, and there is not enough information to say for sure why some people put on weight. It could, for example, be because propranolol can make you feel tired which could make you less active. It could also affect the way your body uses energy. If you're worried about putting on weight with propranolol, speak to your doctor. Will it affect my contraception? Propranolol will not stop your contraception working. However, some types of hormonal methods of contraception, like the combined pill and contraceptive patch, are not usually recommended if you're taking propranolol or other medicines for high blood pressure. This is because some hormonal contraceptives can raise your blood pressure and stop propranolol working properly. Talk to your doctor if you're taking a hormonal contraceptive. If propranolol makes you sick (vomit) or have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do. Read more about what to do if you're on the pill and you're being sick or have diarrhoea. Will it affect my fertility? There is no evidence that propranolol affects fertility in men or women. If you're trying to get pregnant, or you're having problems getting pregnant while on propranolol, speak to your doctor. Will it affect my sex life? Some people on propranolol say their sex drive goes down and some men find they cannot get an erection. However, this is not a common side effect and there is not enough evidence to say for sure that propranolol is causing it. If you're having problems with your sex life, talk to your doctor. Do I need to avoid playing sports? You do not need to stop playing sports if you take propranolol. But do not push yourself too much. Regular exercise is good for you because it lowers blood pressure by keeping your heart and blood vessels in good condition. Be aware, though, that in some sports propranolol is not allowed if you're competing at a high level. Can I drive or ride a bike? Propranolol can make some people feel dizzy, especially when they first start taking it or after taking a bigger dose. If this happens to you, do not drive a car, ride a bike, or use tools or machinery. It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive. Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking propranolol. GOV.UK has more information on the law on drugs and driving. Can lifestyle changes help? If you have heart problems, you can boost the health of your heart by making some key lifestyle changes. These changes will also help if you have high blood pressure.
If you get severe headaches, there are steps you can take to help prevent migraines. This includes working out what things trigger an attack so you can avoid them. What heart rate is too low on beta blockers?Beta blockers can cause your heart to pump with less force, which can lead to bradycardia (slow heart rate). Your heart rate is usually considered too low when it beats less than 60 times per minute while you're at rest. This side effect may not always be noticeable.
What happens to the heart rate if a patient takes beta blockers?Sheps, M.D. Beta blockers slow the heart rate, which can prevent the increase in heart rate that typically occurs with exercise. This means that it might not be possible for you to reach your target heart rate — the number of heartbeats per minute you typically aim for to ensure you're exercising hard enough.
How much will propranolol 20 mg lower heart rate?Compared to placebo, propranolol 20mg effected a lower standing HR at 1 hour (90±13 min−1 vs. 110±18 min−1; P<0.001), and this difference was maintained at P<0.001 for the 4 hours following study drug administration.
How long does propranolol keep heart rate down?For most people, Propranolol can provide around four hours of symptom relief. During this time, Propranolol helps with the physical symptoms of anxiety, such as flushing, increased heart rate, shaking, and sweating.
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