Doxycycline vs Bactrim: Differences, Similarities, side effects, more

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Medical science has gone a long way from penicillin, the first antibiotic ever discovered, which has saved countless lives over the decades. Today, many types of antibiotics are available for an array of applications. Among these types of antibiotics are doxycycline and Bactrim. So which one is more effective? Which one is safer? In this article, we’ll break down the difference between doxycycline vs Bactrim to see their significant differences and how they apply to patients.

Both are used in eliminating several types of bacteria that cause infections. However, they work differently and create different effects on the body.

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What Is Doxycycline?

Doxycycline is a broad-spectrum antibiotic that belongs to a class of antibiotics called tetracyclines. It’s sold under the brand names Vibramycin, Oracea, Atridox, and Acticlate, among others.

This medication works by entering a bacterium and interrupting its cell production process. Binding with specific ribosomal subunits prevents the synthesis of amino acids used in protein chains, so the bacteria cannot replicate.

Doxycycline works in tandem with the immune system. As it kills the bacteria, doxycycline prevents them from replicating and overwhelming the white blood cells, lymphocytes, and antibodies.

Doxycycline can come in three different forms, a generic drug, an oral prescription drug, or a solution for injection. Before you use any form of this drug, it is advised that you consult a professional healthcare provider.

What Is Doxycycline Used For?

As a broad-spectrum drug, doxycycline is used in an array of applications. It is usually prescribed for pelvic inflammatory disease, Lyme disease, periodontitis, and acne.

Additionally, medical professionals use the drug for antibiotic prophylaxis. In essence, it is effective as a prevention method against some infections. Doxycycline is usually recommended for people traveling to places known for severe malaria cases.

Aside from antibacterial properties, doxycycline can combat parasites. It kills the bacteria in the reproductive tracts of roundworms or nematodes, rendering them sterile.

In addition, doxycycline can be administered in tandem with other antibiotic medications. By working with these other drugs, doxycycline hastens the recovery of patients.

What Is Bactrim?

Bactrim is a brand name for a combination of two antibiotics, sulfamethoxazole, and trimethoprim. This fixed-dose combination has five parts sulfamethoxazole and one part trimethoprim.

While Bactrim is the most well-known brand name, others are available, such as Septra and Sulfatrim.

Bactrim works similarly to doxycycline by preventing the growth or multiplication of bacteria. However, the former works in another aspect of cell division.

Bactrim blocks two steps in protein and nucleic acid synthesis inside the cell, disrupting replication. However, this only works against bacteria. Sulfamethoxazole and trimethoprim do not affect viruses.

What Is Bactrim Used For?

Bactrim is another broad-spectrum antibiotic that works against many gram-negative bacteria. That’s why it’s used extensively in treating urinary tract infections (UTIs), middle ear infections, and some respiratory tract infections.

In particular, Bactrim prevents and treats pneumocystis pneumonia, a rare but dangerous type of pneumonia.

The drug is commonly used for patients with compromised immune systems. This includes people with HIV or AIDS, people undergoing chemotherapy for cancer, and patients undergoing organ transplants.

Doxycycline vs Bactrim: Differences

While both are antibiotics, doxycycline and Bactrim have a few fundamental distinctions.

Ingredients: Doxycycline comprises a single antibiotic base, while the rest of the tablet or suspension is composed of stabilizers and dyes.

On the other hand, Bactrim is a combination of sulfamethoxazole and trimethoprim working in synergy to stop bacteria.

Types of Infections Treated: Both doxycycline and Bactrim combat various infections. However, depending on specific diseases and situations, one will likely be more effective than the other.

Side Effects and Drug Interactions: Patients will feel different side effects with either medication, which we’ll discuss further below.

In addition, the two drugs will interact with other medicines and food that patients take. These could either heighten their effects or render them ineffective.

Doxycycline vs Bactrim: Which Is More Effective?

As we’ve discussed, the applications of doxycycline and Bactrim are different. Even though these two are antibiotics, they affect specific types of bacteria. So one will not be more effective than the other.

For example, doxycycline is the drug of choice for periodontitis and acne. This is because the drug has fast-acting properties that only last for a short time, making it ideal for conditions that can be resolved quickly.

On the other hand, Bactrim is better for some severe cases of pneumonia since it’s more effective at killing the disease-causing bacteria.

Short and Long-Term Outcomes of Doxycycline

A few studies have discussed the short- and long-term outcomes of doxycycline. Since most people only need it for less than a few weeks, the short-term effects are more apparent.

However, its most evident immediate effect is the healing of the infection site.

Notwithstanding, there are a few side effects that patients might experience, including headaches and nausea. We’ll discuss those further below.

The long-term effects are much more dangerous. That’s why medical professionals warn against using doxycycline for longer than four months.

One of the most adverse long-term effects is inflammatory bowel disease and increased intracranial pressure, primarily when used with isotretinoin.

Short and Long-Term Outcomes of Bactrim

Similar to doxycycline, some research has shown Bactrim’s short and long-term outcomes. But unlike the more adverse reactions of doxycycline, Bactrim is more suitable for long-term use. That’s why it’s the preferred antibiotic for people who are immunocompromised.

In addition, the body does a much better job handling prolonged use of Bactrim.

Of course, this doesn’t mean there will be no adverse effects. For example, long-term use of Bactrim can sometimes result in oral thrush or yeast infections.

This is because Bactrim can kill off populations of good bacteria, which then causes other harmful fungi like yeast to multiply and cause infections.

Side Effects of Doxycycline

Not everyone will get side effects from doxycycline. However, some may experience the following mild symptoms:

  • Nausea
  • Vomiting
  • Headaches
  • Feelings of discomfort
  • Loss of appetite

You shouldn’t panic if you experience some of these symptoms, but if they get bothersome, seek medical help.

There are more severe but rare side effects that can occur. Here are symptoms that require immediate medical attention:

  • Bruising and bleeding
  • Severe stomach pain and cramps
  • Allergic reactions like hives, swelling tongue, and itching
  • Difficulty breathing
  • Fever
  • Swollen lymph nodes
  • Painful or difficulty in swallowing
  • Blistering and redness of the skin, including the mouth

Side Effects of Bactrim

Bactrim has similar side effects to doxycycline since they are both antibiotics. Here are the common ones a patient can expect:

  • Dizziness
  • Loss of appetite
  • Sleeping problems
  • Spinning sensation
  • Ringing ears
  • Nausea and vomiting
  • Tiredness

7 Common Side Effects of Bactrim

If any of the following become bothersome or severe, seek immediate medical help.

There are other severe side effects other than those outlined above. Though rare, they must be immediately addressed to avoid further complications.

Patients who feel or recognize the following side effects must get medical help as soon as they can:

  • Severe skin rashes
  • Mouth sores
  • Bruising or bleeding
  • Jaundice
  • Aching joints

What Drugs Interact With Doxycycline?

Doxycycline, like most other drugs, will be affected by and affect other medications. That’s why it’s essential for patients to be upfront with their doctor about the kind of medicine, prescribed or otherwise, that they take.

In general, calcium supplements, laxatives with magnesium, iron supplements, and antacids can weaken the effect of doxycycline.

Doxycycline shouldn’t be used with penicillin to augment the latter’s bacteria-killing effects.

These two will only interfere and cause both to be ineffective, prolonging the duration of the infection. Patients must also avoid taking it with isotretinoin as the combination can cause an increase in intracranial pressure.

What Drugs Interact With Bactrim?

The combination of sulfamethoxazole and trimethoprim heightens the blood-thinning effects of certain medications. To avoid bleeding, a patient must not take them with drugs like warfarin.

In addition, sulfamethoxazole can crystallize in acidic urine, causing kidney stones.

This same component can increase the breakdown of cyclosporine, which can cause kidney damage.

If combined with specific ACE inhibitors for treating blood pressure, Bactrim can result in increased blood potassium levels. In addition, some medications react with Bactrim, such as Divalproex and valproic acid, which cause a drop in folic acid levels. If left unchecked, this effect can result in anemia.

Which Foods Interact With Doxycycline?

It’s not only medications that interact with doxycycline. Some foods contain compounds and substances that interact with the drug, weakening or heightening its effects.

For example, the calcium in dairy reduces the body’s ability to absorb doxycycline, so patients must avoid drinking milk while taking doxycycline.

Iron-rich foods also inhibit the absorption rate of doxycycline, so avoid eating sardines, eggs, kale, spinach, beef, and other foods high in iron before taking the drug. Ideally, these should be spaced out by at least two hours.

Finally, consuming alcohol is highly discouraged for patients taking doxycycline or any antibiotic. It can aggravate the side effects mentioned above and make doxycycline less effective.

Which Foods Interact With Bactrim?

When taking Bactrim, avoid eating foods that contain propylene glycol, a compound used in processed foods, medicine, and soda drinks. The combination can cause lactic acidosis, which is the build-up of lactic acid in the blood.

Avoid dried soups, salad dressings, seasoning blends, baking mixes, powdered drink concentrates, and other similar items.

Similar to doxycycline, Bactrim will have adverse reactions to alcohol. Mixing these two can elevate blood pressure and heart rate, causing stress to the cardiovascular system.

Doxycycline vs Bactrim for Pregnant or Breastfeeding Women

Unfortunately, doxycycline is not recommended during pregnancy. A few studies have linked it to higher chances of miscarriage, so doctors need to prescribe other types of antibiotics. In addition, the drug may affect the baby’s bone and tooth development.

On the other hand, Bactrim shouldn’t be taken by pregnant women during the first trimester of pregnancy. This is because research has shown a small risk of congenital disabilities for those who take this drug.

Doxycycline Dosage

Doxycycline is available in both oral and intravenous forms, the latter being used for more severe cases of infection.

For those who’ll take it orally, the typical dosage is 100 mg every 12 hours on the first day, then 50 mg to 100 mg daily for adults and children above 88 pounds.

Doxycycline hyclate and monohydrate are the two generic forms available today, and the only difference is the salt form. The dosage will be the same, regardless of which form a patient takes.

Bactrim Dosage

Bactrim is available in an injected solution, oral suspension, and tablets. The dosage is different according to the type of infection being addressed. But in general, adults and children two months and older need to take 300 mg of sulfamethoxazole-trimethoprim twice a day for 14 days.

Doctors may increase the dosage depending on the severity of the case, but the maximum amount should be 960 mg of trimethoprim a day.

Can Doxycycline and Bactrim Be Used Together?

So far, no interactions have been found between doxycycline and Bactrim. But this doesn’t mean that there aren’t any — medical science may not have just found them yet. So, for now, patients should exercise caution and consult a medical professional before taking them together.

How Should Doxycycline Be Taken?

To avoid interactions, those using tablets take this drug on an empty stomach, preferably one to two hours before their next meal. Then, drink it with a glass of water while sitting or standing. After taking the medication, avoid lying down to prevent throat irritation.

How Should Bactrim Be Taken?

Drink the tablet with a glass of water. It can be taken on a full or empty stomach, but if a patient feels irritated, it’s best to take it after a meal. Because of Bactrim’s potential side effects on the kidneys, patients should drink plenty of fluids while on this medication.

Upsides of Doxycycline and Bactrim

Doxycycline and Bactrim are very effective at what they do. They work in tandem with the immune system, halting cell division among bacteria while white blood cells and antibodies eliminate them.

Both drugs are also broad-spectrum antibiotics, which means they can target a wide array of bacteria species.

Downsides of Doxycycline vs Bactrim

Doxycycline doesn’t have many downsides except its interactions with certain hormone medications and isotretinoin. It’s also recently been found to affect the proliferation of human cell lines.

On the other hand, Bactrim can have severe effects on the kidneys and the urinary tract. So a patient needs to follow a doctor’s advice and report any issues immediately when taking the drug.

Frequently Asked Questions

Doxycycline is effective against tooth infection and is often used along with other antibiotics for the best results. 

Penicillin is usually the first antibiotic used for staph infections. If the bacteria is resistant, then Bactrim and others may be used. 

Bactrim isn’t the first choice for tooth infections. Instead, doxycycline is more commonly used. 

It’s a potent antibiotic for the bacteria it’s made to treat. But if those have gained resistance, then the drug will not work. 

It is safe and effective for kidney infections but is not the first choice among medical professionals. 

When taken at the proper dosage, Bactrim should be relatively safe. Of course, side effects are expected, but they are typically mild. 

Bactrim takes about a week before it clears out of the body, while doxycycline takes about five days. 

Yes, Bactrim can treat a staph infection, but it’s not usually the first choice. 

Yes, fruit juices, especially acidic ones, can interact with antibiotics. So avoid taking them together. 

It will stay in the body for around five days before altogether leaving. 

There is no waiting time since these two drugs don’t interact with each other. 

There is no better antibiotic. Both have specific applications that the other doesn’t. 

It’s a strong antibiotic for the bacteria it’s made for. But if those organisms are resistant, then the drug will not work. 

Many types of bacteria are treated with Bactrim, both gram-negative and gram-positive. 

Yes. They don’t interact with each other but take them together only with medical supervision.

The content on Doctor Alexa’s blog is reviewed by Advanced practice registered nurses or pharmacist and is intended for educational purposes only. This information should not be relied upon as professional medical counsel. Be sure to always consult with your physician about the dangers and benefits of any medication, treatment or procedure.

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