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When sinus pain strikes it can leave you feeling low. Your face throbs, your head aches and your nose feels stuffy, making it hard to concentrate on everyday tasks. If it’s viral it usually clears up on its own in a few days. But if your symptoms last for ten or more days without improvement it’s more likely to be bacterial sinusitis. This is when Phenoxymethylpenicillin (Pen V) can help.
It's the first-choice antibiotic treatment recommended by NICE to help relieve acute sinusitis and get you back to normal fast. So, if you’ve been suffering with sinusitis for a while now, it’s time to get in touch and speak to one of our healthcare professionals.
Pen V is only available on prescription so our clinical team will ask you a few questions first and make sure it’s the right treatment for you. Once approved, we will dispatch your medication straight away, delivering it directly to your door so that you can start feeling better as quickly as possible.
Phenoxymethylpenicillin (Pen V) is a penicillin-based antibiotic used to treat certain infections, including acute bacterial sinusitis. If you have a sinus infection which hasn’t cleared up after ten or more days, it could indicate it’s a bacterial rather than a viral infection, and our UK clinical team may prescribe Pen V to get rid of it.
It’s an effective antibiotic and considered the first-choice treatment for bacterial sinusitis, helping to reduce inflammation and ease symptoms like facial pain and congestion.
Bacterial sinusitis occurs when bacteria infect your sinus cavities – the air-filled spaces behind your nose and face. This causes inflammation, congestion, pressure and pain in your head and face.
Pen V works by directly attacking these bacteria and supporting your immune system. It blocks their ability to produce strong cell walls which they need to survive. Without proper cell walls the bacteria weaken, break apart and die.
NICE recommends you should take two 250mg tablets four times a day for five days on an empty stomach. This should be spaced evenly throughout the day, for example first thing in the morning, at midday, later afternoon and before bedtime.
Avoid taking Pen V at mealtimes because taking it with food can make it less effective. Instead, take it either 30 minutes before you eat or two hours after you’ve eaten.
The active ingredient in Pen V is phenoxymethylpenicillin. Each tablet contains 250mg phenoxymethylpenicillin as phenoxymethylpenicillin potassium.
The tablets contain 28mg potassium which may be harmful to people on low sodium diets or with reduced kidney function.
Like any medication, Pen V can cause side effects although not everyone will experience them. Common side effects include nausea, being sick, diarrhoea, thrush or inflammation of the vaginal area and soft stools. If you’re worried about anything related to your treatment, speak to our healthcare professionals.
However, if you experience severe diarrhoea, vomiting, signs of an allergic reaction such as difficulty breathing, swelling of the face, lips and throat, or unusual bleeding or bruising you should stop taking the medication and seek medical attention immediately.
While Pen V is an effective antibiotic it’s not suitable for everyone. You should not take it if you’re allergic to penicillin or other antibiotics.
If you have kidney problems or other conditions which affect your metabolism it’s also not suitable. Some medications, such as methotrexate or blood thinners, may interact with Pen V and affect how it works. During your consultation, tell our healthcare professionals about any allergies, medical history, or other medicines you’re taking before starting treatment so we can ensure it’s safe for you.
Acute sinusitis occurs when you have an infection of the sinus cavities – the air-filled spaces behind your nose and face. It’s common with a cold or flu, causing a blocked or runny nose, congestion, inflammation, pressure and pain around your face and head. Most cases clear up by themselves after a few days. Rest, fluids and over-the-counter medicines can help ease your symptoms and give your body a chance to fight off the infection.
But if your symptoms last more than ten days, worsen, or come back after initially improving it could be bacterial, in which case antibiotics like Pen V may help. These attack the bacteria, weakening their cell walls and causing them to die.
However, antibiotics only treat bacterial infections, not viral - it’s important we understand your symptoms and how long you’ve had them so we can get you the right treatment.
Pen V is recommended by NICE as the first-choice antibiotic for treating acute bacterial sinusitis because it is effective in targeting the bacteria that cause the infection.
It’s a narrow-spectrum antibiotic which means it focuses on specific bacteria rather than wiping out a broad range. This helps reduce antibiotic resistance. When symptoms last more than ten days, Pen V offers a safe, effective option to clear your infection and help you feel better.
The recommended dose is 500mg four times daily for five days. You should space your doses evenly throughout the day and take them on an empty stomach, either 30 minutes before food or two hours after as taking them with a meal can reduce their effectiveness.
It’s important you complete the entire course of antibiotics even if you start to feel better sooner. If you don’t, some bacteria may remain, the infection could come back and be harder to treat in future.
While antibiotics can help there are plenty of things you can do to ease your symptoms at home. NICE recommends pain relievers like paracetamol and ibuprofen to reduce pain, headaches and fever while your body fights the infection.
Nasal saline irrigation – rinsing the nasal passages with salt water – can help clear mucus, reduce pressure and ease congestion.
Drink plenty of water or other fluids, rest as much as you can and use warm compresses on your face to ease any discomfort.
Most sinusitis cases are caused by a virus and clear up on their own within two to three weeks. Rest, self-care and plenty of fluids can help you feel better as well as give your body more chance to fight off infection.
If your sinusitis is bacterial and you’re given antibiotics to clear it, you may notice an improvement in two to three days. However, it’s important to take the entire course even if you are feeling better.
The most common side effects of Pen V are diarrhoea and feeling/being sick, thrush or inflammation of the vaginal area, soft stools and sometimes a mild skin rash.
If you experience diarrhoea stay hydrated, drinking water or squash, to replenish lost fluids. Stick to simple meals, nothing spicy, during treatment. Get plenty of rest and relaxation. If you’re sick or suffer stomach pain, try eating smaller, more frequent meals.
Mild allergic reactions can be treated by taking antihistamines, but in the case of a serious allergic reaction call 999 or visit your hospital’s emergency department.
If you’re allergic to penicillin you shouldn’t take Phenoxymethylpenicillin as it belongs to the same group of antibiotics and could trigger a reaction. Symptoms range from mild such as a skin rash to severe – difficulty breathing, swelling of the throat, neck and face.
If you have a known allergy, tell our healthcare professionals during your consultation and they’ll prescribe an alternative like Clarithromycin or Doxycycline.
It’s important you tell us about any other medicines you’re taking as Pen V can affect how well they work. You should tell us if you’re taking gout or blood thinning treatments or medication for kidney, liver or blood problems. You should also let us know if you’re pregnant, trying for a baby or breastfeeding.
If you’re taking oral contraceptives Pen V may make it less effective. Our medical professionals will tell you whether you need additional contraception during treatment.
While most sinus infections clear up either on their own or with the help of antibiotics like Pen V, you should seek urgent medical attention if you experience severe symptoms.
These include a high fever (over 102°F or 39°C), severe headaches, pressure or facial pain, stiffness around the neck or difficulty breathing, confusion, double vision or changes in vision.
The effects of Pen V during pregnancy are not fully known so if you’re pregnant or trying for a baby you should let our healthcare professionals know during your consultation. They’ll decide whether it’s suitable for you to take during pregnancy or offer an alternative.
Pen V also appears in breast milk so if you’re breastfeeding it’s essential you let us know too. Again, our medical professionals may offer an alternative or advise you to pause breastfeeding during treatment.
Ordering Phenoxymethylpenicillin 250mg tablets online with The Independent Pharmacy is simple and hassle-free. Because it’s a prescription-only medicine, you’ll need to answer some quick health questions first. The consultation is discreet and only takes a few minutes.
Our healthcare professionals will review your answers and recommend the best treatment for your individual needs. Once approved, your medication is delivered straight to your door, with next-day delivery available. Start today and get fast relief from sinusitis.
We think accessing healthcare should be easy. Whether we’re fulfilling NHS prescriptions or helping people find the right treatments, we aim to offer our customers dependable, economical and convenient access to medicines with a personal and discreet service.
Visit our Sinusitis page for treatments, advice and FAQs.
