UTI and Cystitis Tablets in Hong Kong: Which Antibiotics, How Long

Burning as you pee, an urge that arrives with no warning, and the nagging feeling that you need to go again the moment you stand up. If that is your day, the cause is usually cystitis, an infection of the bladder lining. Urinary tract infections take in cystitis, urethritis and kidney infection, and most of what people call a UTI is cystitis in the bladder. Antibiotics are not always needed, and a doctor may suggest a 48-hour wait to see whether your body clears it on its own.

Whether the infection sits low in the bladder or higher up in a kidney changes the tablets, the length of the course and how quickly you need help.

In short

• Most burning, urgency and frequency is cystitis, and it is usually treated with a short antibiotic course plus paracetamol for the sting.
• Fever, shivering, back or side pain, or being sick points to a kidney infection, which needs urgent medical attention and a longer course.
• For non-pregnant women, NICE's first choices are nitrofurantoin for three days, or trimethoprim for three days when resistance risk is low.
• Finish the whole course even when you feel better, and get help if nothing has improved within 48 hours.

How do I tell cystitis from a kidney infection?

Two days of burning, and up twice in the night: is this ordinary cystitis, or something that needs a hospital? The symptoms overlap, so the distinction is worth knowing.

Cystitis shows up as pain or a burning feeling when you pee, needing to pee more often and more suddenly, needing to go at night, cloudy pee, blood in pee, pain low in your tummy, and feeling tired or weak. A high temperature can appear too, along with feeling hot, cold and shivery. The NHS lists all of these among the symptoms of a urinary tract infection.

A kidney infection is a painful UTI that can affect one or both kidneys and is serious if it is not treated. Alongside the bladder symptoms you may have a high temperature, feel or be sick, get pain in your lower back or side, diarrhoea, aching muscles and a flu-like feeling, as the NHS kidney infection page explains. Because the two can look alike at the start, the signals that tip you towards a kidney infection are fever, shivering, and pain in your back or side rather than low in your tummy.

Some situations call for urgent advice rather than waiting. The NHS includes being 65 or older, a very high or very low temperature (below 36C) or shivering, being a man, having diabetes, using a catheter, being pregnant, having a weakened immune system, pain in your lower tummy or back just under the ribs, blood in your pee, or symptoms that get worse quickly. If someone becomes confused, drowsy or has difficulty speaking, that is an emergency, because a kidney infection can lead to sepsis.

Which antibiotics are used for cystitis, and how long is the course?

One person is told three days and a friend took a week. The length depends on who you are, not on how bad the burning feels.

For non-pregnant women aged 16 and over, NICE's guideline NG109 on lower urinary tract infections puts nitrofurantoin first, at 100mg modified-release twice a day, or 50mg four times a day if the modified-release version is unavailable, for three days. That applies when kidney function is at an eGFR of 45 ml/minute or more. Trimethoprim 200mg twice a day for three days is the other first choice, used when the risk of resistance is low. Not having used trimethoprim in the past three months makes resistance less likely.

The second choices come in when there is no improvement after at least 48 hours on the first choice, or when the first choice is unsuitable for you. Local resistance matters here. NICE tells prescribers to take local antimicrobial resistance data into account, so the best antibiotic depends on where you live. We have not been able to read a Hong Kong guideline, so this article quotes no Hong Kong resistance figures.

Men are treated differently, and so are pregnant women. A man with these symptoms gets an immediate antibiotic and a urine culture taken before it starts, usually trimethoprim 200mg twice a day for seven days or nitrofurantoin for seven days. Nitrofurantoin is not recommended where the prostate may be involved, because it is unlikely to reach therapeutic levels there. In pregnancy the advice is an immediate antibiotic plus a midstream urine culture before starting: nitrofurantoin first choice for seven days but avoided at term, with amoxicillin (only when a culture shows the bacteria are susceptible) or cefalexin as second choices, also for seven days.

How is each tablet taken, and which side effects matter?

A handful of points about timing, food and side effects cover most of what you need.

Nitrofurantoin is swallowed whole, with the doses spaced evenly through the day. Taking it with food or a glass of milk helps it work and softens the nausea that some people get. Leave about two hours between nitrofurantoin and any antacid, because antacids reduce how much you absorb. Your pee may turn dark yellow or brown, which is expected. The common side effects are nausea, diarrhoea, loss of appetite and headaches; the NHS page on nitrofurantoin sets them out. More serious effects are uncommon but worth knowing: lung problems such as a cough or breathing trouble, liver problems with jaundice, a severe allergic reaction, blood problems showing as unexplained bruising or bleeding, a sore throat or high temperature, and severe headaches. It may not suit you if you have had a reaction to it before or you have a lung condition. Nitrofurantoin works in the bladder and is not the right medicine for a kidney infection.

Trimethoprim is used for infections including UTIs such as cystitis, according to the NHS trimethoprim page. Co-trimoxazole pairs sulfamethoxazole with trimethoprim in 400/80mg and 800/160mg tablets, and it is most often used for urinary tract infections. It is not for you if you have a sulfonamide allergy, and it raises potassium, so it needs care alongside spironolactone, amiloride, ACE inhibitors or ARBs; the co-trimoxazole product page covers this. NICE lists trimethoprim on its own rather than the combination.

Ciprofloxacin belongs to the fluoroquinolone group, which the MHRA now says should only be used when other commonly recommended antibiotics are inappropriate. They can cause serious, long-lasting or disabling effects on tendons, muscles, joints, nerves and mental health. Stop at the first sign of tendon pain, muscle pain or weakness, joint pain or numbness and contact a doctor immediately, and take extra care if you are over 60 or have kidney problems. Ciprofloxacin is not a first choice for simple cystitis.

Cephalexin is a cephalosporin sold as 500mg tablets. NICE lists cefalexin as a second choice in pregnancy only, so it is not a first choice for simple cystitis either.

What eases the burning while the antibiotic starts working?

Antibiotics take a little time to bring the burning down. In the meantime:

For the pain and any temperature, paracetamol up to four times a day. Rest, and drink enough to pass pale pee regularly. The NHS UTI guidance also says fruit juice, coffee and alcohol can irritate the bladder, so cut back. Cystitis sachets and cranberry drinks? They may help some non-pregnant people prevent UTIs. There is no evidence they ease symptoms or treat an infection that has already started.

Phenazopyridine is the one that catches people out. It relieves urinary pain, burning, irritation and discomfort, along with urgency and frequency, but it is not an antibiotic and does not cure infections. It is usually taken three times a day after meals and swallowed whole with a full glass of water, because chewing or crushing it can stain your teeth. Stop it when the pain and discomfort go. Your urine may turn red-orange or brown, which is harmless. Headache, dizziness and upset stomach are possible. Call a doctor for yellow skin or eyes, fever, confusion, blue or purple skin, shortness of breath, a rash, a sudden decrease in urine or swelling, and tell your doctor if you have kidney disease or G6PD deficiency. Think of it as a painkiller that works on the urinary tract, running alongside a proper antibiotic rather than replacing it.

When is it urgent, and who needs more than a short course?

Two doses in and feeling worse, or a man with these symptoms for the first time: the usual three days may not apply.

Get advice from a GP or urgent care service if you are 65 or older, have a very high or very low temperature or are shivering, are a man, have diabetes, use a catheter, are pregnant, have a weakened immune system, have pain in your lower tummy or back just under the ribs, or have blood in your pee. The same goes for symptoms that get worse quickly, or that have not improved within 48 hours of starting treatment or of treating it yourself, and for two UTIs within six months or three within twelve. Call emergency services if someone becomes confused, drowsy or has difficulty speaking.

Men, pregnant women, people with diabetes, people with a catheter, those aged 65 and over and anyone getting repeated infections need a urine test and a course planned around their situation rather than the standard three days.

How do I stop it coming back?

Some people get one bout a year, others one every couple of months. The NHS prevention advice is plain but practical.

Most of it is habit. Wipe front to back. Keep the area clean and dry, and wash with water around the vagina before and after sex. Pee soon after sex. Change soiled pads promptly, wear cotton underwear, and drink plenty of fluids through the day. Things to avoid: scented soap, holding in pee, rushing when you go, tight underwear, a lot of alcohol, lots of sugary food and drink, and condoms, a diaphragm or a cap used with spermicidal lube.

If cystitis keeps returning, there is some evidence that daily D-mannose or cranberry products may help. Both can contain a lot of sugar, and cranberry should be avoided with warfarin; speak to your doctor about them in pregnancy. For recurrent infections a GP may offer a different antibiotic, a low-dose antibiotic for up to six months, vaginal oestrogen after the menopause, or a referral.

Which UTI tablets does PockDose list?

For the full range, see the urinary tract infections page; symptom relief is under urinary pain. What we list:

Fosfomycin, pivmecillinam and plain trimethoprim tablets are guideline options that PockDose does not list, so you will not find them here. Everything above is a generic medicine, and ordering needs no prescription. Ciprofloxacin and cephalexin are not NICE's first choices for simple cystitis. The product page shows the strength and form of each listing, so check it before you order. Finish the course you start, even if the burning has gone by day two, and keep drinking enough water to pass pale pee. The antibiotics category has the rest of the range.