Oral STI Medications

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Introduction   

When hearing the phrase sexually transmitted infections, what comes to mind? If you're an advanced practice registered nurse (APRN) with prescriptive authority, you've definitely heard of sexually transmitted infections (STIs) before. Even as a nurse or maybe before nursing school, conversations about prescription drug use and sexual health existed every so often.

Presently, patients seek guidance and information on various health topics from APRNs, including medication management and sexual health. The information in this course will serve as a valuable resource for APRNs with prescriptive authority of all specialties, education levels, and backgrounds to learn more about oral medications that can treat and manage STIs.

Defining Sexually Transmitted Infections (STIs) 

What Are STIs? 

Sexually transmitted infections (STIs) are infections that transmitted via sexual activity, such as oral sex, vaginal sex, anal sex, and sexual skin-to-skin contact. STIs can be bacterial, viral, and parasitic in nature and infect millions of people in the USA and around the world every year. STIs can be stigmatized as only common among those who are poor or unhoused, but it is important to note that anyone who is engaging in sexual activity is at risk for a STI (1).  

What Are Bacterial STIs? 

Bacterial STIs include chlamydia, gonorrhea, syphilis, bacterial vaginosis, chancroid, and mycoplasma genitalium.  

Chlamydia is the most common bacterial STI in the United States and a leading cause of infection-related vision loss worldwide. Chlamydia is a bacterial infection as a result of exposure to the Chlamydia trachomatis bacterium via sexual contact.  

Gonorrhea is another common bacterial STI in the United States and is a bacterial infection as a result of exposure to the Neisseria gonorrhoeae bacterium via sexual contact.  

In addition, syphilis is another bacterial infection as a result of exposure to the spirochete Treponema pallidum bacteria via sexual contact (4). Syphilis rates in the United States were once very minimal but have increased significantly over the past few years (4).  

Bacterial vaginosis is a vaginal condition in which there is an imbalance of bacteria in the vaginal microbiome (5). Several cases of bacterial vaginosis can be related to vaginal sexual activity; however, people can have bacterial vaginosis anytime there is an imbalance of bacteria in the vaginal microbiome (5).  

Chancroid is a bacterial infection that is a result of exposure to the H. ducreyi bacterium via sexual contact (6). Chancroid prevalence in the United States has decreased over the past several years but is still a bacterial STI of concern (6).  

The final bacterial STI for this course is mycoplasma genitalium, in which someone is exposed to this bacterium via sexual contact.  

What Are Viral STIs? 

Viral STIs include herpes simplex virus (HSV), human papillomavirus (HPV), and human immunodeficiency virus (HIV). HSV, also known as herpes, is a chronic viral infection that is transmitted via sexual skin-to-skin contact and sexual activity (8). HPV is the world's most common sexually transmitted infection, a chronic viral infection, and is transmitted via sexual skin-to-skin contact and sexual activity (9).  

HIV is a chronic viral infection transmitted via blood, semen, vaginal secretion, or breastmilk that can progress to acquired immunodeficiency syndrome (AIDS) if left untreated and unmanaged (10).  

What Are Parasitic STIs? 

Trichomoniasis is a parasitic STI that is a result of being exposed to the Trichomonas vaginalis protozoan parasite via sexual activity (11).  

What If STIs Are Left Untreated? 

Depending on the STI, STIs can cause several long-term complications if left untreated. If HIV is not properly managed, several complications, such as AIDS and immune-related deficiencies, can emerge (10). Untreated or repeated chlamydia and gonorrhea infections can lead to chronic pelvic pain, genital pain, genital discharge, and infertility (2,3).  

If syphilis is left untreated, neurological, cardiac, and musculoskeletal complications can occur (4). While the most common STI symptom is no symptom, it is important to offer routine STI screening and be able to assess and manage positive STI results if they occur.  

Defining Oral STI Medications 

Oral STI medications depend on the type of infection being treated or managed. Bacterial STIs are treated with antibiotics, and some viral STIs are managed with antiviral medications. The most common oral STI medications are azithromycin, metronidazole, acyclovir, and doxycycline.  

Oral STI medications are used in various clinical settings, such as hospitals, outpatient clinical settings, public health departments, correction facilities, and more. Oral STI medications are prescribed and then taken by mouth. Depending on the dosage and type of STI, someone might take only one pill of an antibiotic to cure chlamydia or take a series of pills to manage their HIV viral load.  

What are the Clinical Criteria for Prescribing Oral STI Medication? 

Clinical criteria for prescribing oral STI medications can vary depending on the STI itself. First, a health care provider would order and perform testing to detect STIs, such as a Pap smear, urine sample, visual examination, blood sample, or genital swab (1,2,3,4,9).  

If any of these tests show a positive result for an STI, clinical guidelines from reputable organizations, such as the Centers for Disease Control and Prevention (CDC) or the National Institutes of Health (NIH), are followed to manage these conditions (1, 2). In addition, local laws and health departments might have reporting requirements if a patient tests positive for an STI, so be sure to check with your local boards of nursing or health department on any reporting requirements.  

What Is the Average Cost for Oral STI Medications? 

Cost for oral STI medications can significantly vary depending on the type of medication, insurance, dosage, frequency, and other factors. Cost is among a leading reason why many patients cannot maintain their medication regime (12). If cost is a concern for your patient, consider reaching out to your local pharmacies or patient care teams to find cost effective solutions for your patients.  

Antibiotic Pharmacokinetics  

Drug Class – Oral Antibiotics for STIs 

Health care provider professional discretion and patient condition should guide therapy. Consider reviewing a patient’s medication history and health history prior to prescribing oral medications for STIs.  

Bacterial STIs include chlamydia, gonorrhea, syphilis, bacterial vaginosis, chancroid, and mycoplasma genitalium. 

Oral Antibiotics Method of Action 

The method of action for oral antibiotics for STI treatment depends on the antibiotic and the type of bacterium present.  

Chlamydia infections are a result of exposure to the chlamydia trachomatis bacteria. A chlamydia infection can be treated with a course of doxycycline 100mg pills twice a day for seven days. Alternative treatment options include azithromycin 1 g pill as a single dose or levofloxacin 500mg pill once a day for seven days (1,2). 

Doxycycline is an antibiotic that is part of the tetracycline drug class and works by preventing the growth of gram-negative and gram-positive bacteria, such as chlamydia trachomatis, Neisseria gonorrhoeae, and spirochete Treponema pallidum (13). Doxycycline works to eliminate the chlamydia trachomatis bacteria by binding to the 30S prokaryotic ribosomal unit during the protein synthesis, thus slowing down and eliminating the growth of bacteria (13).  

Azithromycin and erythromycin are antibiotics that are part of the macrolide drug class and work by preventing the growth of many gram-negative and gram-positive bacteria (14). Azithromycin and erythromycin work to eliminate the chlamydia trachomatis bacteria and Hemophilus ducreyi by binding to the 50S subunit of bacterial ribosomes and leading to decreased bacterial synthesis (14).  

Levofloxacin is an antibiotic that is part of the fluoroquinolone drug class and works by directly stopping bacterial DNA synthesis, as levofloxacin is considered to have the strongest activity against gram-positive, penicillin-sensitive, and resistant bacterium (15). Levofloxacin works to eliminate the chlamydia trachomatis bacteria by breaking the DNA strands through DNA-gyrase inhibition (15).  

Gonorrhea infections are a result of exposure to the Neisseria gonorrhoeae bacteria. Gonorrhea infection treatment guidelines include a single injection of ceftriaxone depending on the patient’s weight (16). If ceftriaxone is a contraindication for the patient’s condition or unavailable, gonorrhea can be treated with a course of doxycycline 100mg pills twice a day for seven days (16). 

Syphilis infection is a result of exposure to the spirochete Treponema pallidum bacteria (4). Syphilis infection treatment guidelines include benzathine penicillin injections, where the dosage and frequency depend on the stage of syphilis, patient age, and other co-existing health conditions. Some guidelines also recommend doxycycline 100mg pills twice a day for 14 days; however, penicillin injections appear to be more effective at syphilis management and treatment (4).  

Bacterial vaginosis is not always STI, as bacterial vaginosis is the result of an imbalance of bacteria in the vaginal microbiome. However, regardless of the cause of bacterial vaginosis, current guidelines for bacterial vaginosis treatment includes metronidazole pills at 500mg twice a day for seven days with possible intravaginal application of metronidazole or clindamycin as well (5).  

Metronidazole is a medication that is part of the nitroimidazole antimicrobial and antiprotozoal drug class, where its method of action involves protein synthesis inhibition (17). Metronidazole works to eliminate bacteria and Trichomonas vaginalis protozoan by causing the destruction of helical DNA structure and strand breakage, causing bacterial death (17). Tinidazole is another medication part of the nitroimidazole drug class, has a similar pharmacokinetic profile to metronidazole, and a higher cure rate for parasitic infections (17). 

Chancroid is a result of exposure to the Haemophilus ducreyi (H. ducreyi) bacteria via sexual contact. Current guidelines for chancroid treatment include either a single dose of azithromycin 1g pill, a single ceftriaxone 250 mg injection, ciprofloxacin 500mg pills twice a day for three days, or erythromycin 500mg pills three times a day for seven days.    

Ciprofloxacin is an antibiotic that is part of the fluoroquinolone drug class, where it works to eliminate the H. ducreyi bacteria by breaking the DNA strands through DNA-gyrase inhibition (18). 

Having Mycoplasma Genitalium as an STI is a result of exposure to this bacterium. Current guidelines for mycoplasma Genitalium treatment depend on the macrolide sensitivity of the bacteria and patient condition. If the mycoplasma Genitalium is macrolide sensitive, the recommendations include doxycycline 100mg pills twice a day for 7 days followed by a single azithromycin 1mg pill, then followed by one 500mg pill once a day for three additional days (7). If the mycoplasma Genitalium is macrolide resistant or if resistance testing is not available, recommendations include doxycycline 100mg pills twice a day for 7 days followed by a single azithromycin 1mg pill, followed by moxifloxacin one 400 mg pill daily for seven days (7). 

Trichomoniasis is a parasitic STI that is a result of being exposed to the Trichomonas vaginalis protozoan parasite via sexual activity (11). Current guidelines for trichomoniasis treatment include metronidazole one 500mg pill twice a day for 7 days for women or a single metronidazole 2g pill for men. An alternative treatment option for both men and women include a single tinidazole 2g pill (11).  

Oral Antibiotic Side Effects 

Every medication has the possibility of side effects, and oral antibiotics are no exception. Possible side effects of doxycycline include photosensitivity, GI upset, headaches, tooth discoloration, and a skin rash (13). More severe side effects of doxycycline include chest pain, leukopenia, changes in heart rate, and hepatoxicity.  

Doxycycline is also contraindicated for pregnant people and children under 12 because of the teratogenic properties and risk of teeth discoloration. Doxycycline is also contraindicated for people who are allergic to tetracycline medications or penicillin (13).  

Possible side effects of azithromycin and erythromycin include hepatotoxicity, GI upset, QT interval prolongation, and cardiac complications. Azithromycin and erythromycin are contraindicated in people who are allergic to macrolides (14). 

Possible side effects of levofloxacin and moxifloxacin include photosensitivity, GI upset, headache, tendon rupture, changes in glucose levels, seizures, QT interval prolongation, and peripheral neuropathy. Levofloxacin and moxifloxacin are contraindicated in pregnancy and breastfeeding patients (15). Levofloxacin has FDA-issued box warnings for side effects related to tendinitis and tendon rupture, peripheral neuropathy, and central nervous system effects (15).  

Possible side effects of metronidazole include peripheral neuropathy, metallic taste, GI upset, and confusion (17). Consuming alcohol and being in the first trimester of pregnancy are contraindications for metronidazole usage (17).  

Possible side effects of ciprofloxacin include GI upset, QT interval prolongation, glucose level changes, and photosensitivity. FDA-issued box warnings for side effects related to ciprofloxacin include tendinitis and tendon rupture, peripheral neuropathy, and central nervous system effects (18). 

Oral Antibiotics Alternatives 

Given the nature of bacterial STIs, the only evidence-based method of treating bacterial STIs is with antibiotic medications (1). Condom use can help prevent the transmissions of STIs1. 

Antiviral Pharmacokinetics  

Drug Class – Oral Antivirals for STIs 

Health care provider professional discretion and patient condition should guide therapy. Consider reviewing a patient's medication history and health history prior to prescribing SSRIs. 

Viral STIs include herpes simplex virus (HSV), human papillomavirus (HPV), and human immunodeficiency virus (HIV).  

Oral Antivirals Method of Action 

HSV, also known as herpes, is a chronic viral infection that is transmitted via sexual skin-to-skin contact and sexual activity (8). Current guidelines for HSV antiviral medication management include one acyclovir 400mg pill twice a day, one valacyclovir 500mg or 1g pill a day, or one famciclovir 250mg twice a day with a duration depending on the severity of the HSV outbreak, patient health history, and clinical presentation. Since HSV is a chronic viral health condition, dosage and frequency can vary from patient to patient.  

Acyclovir and valacyclovir are an antiviral medication part of the antiviral drug class that works by incorporating into viral DNA, thus reducing further HSV synthesis (19). Valacyclovir is the prodrug to acyclovir (19). Famciclovir is a prodrug antiviral medication part of the nucleoside analog antiviral drug class, where its method of action involves inhibiting DNA polymerase, leading to decreased viral replication (20).  

HPV is the world's most common sexually transmitted infection, a chronic viral infection, and is transmitted via sexual skin-to-skin contact and sexual activity (9). There are no oral STI medication options to manage HPV (9). 

HIV is a chronic viral infection transmitted via blood, semen, vaginal secretion, or breastmilk that can progress to acquired immunodeficiency syndrome (AIDS) if left untreated and unmanaged (10). Given the complex pharmacological properties of HIV antiviral medications and HIV clinical manifestations, refer to specialty care for HIV for chronic management or seek additional training if possible (10).  

There are several antiviral medications that can be used to manage HIV depending on the patient's health history, severity of HIV status, and clinical presentation. Oral antiviral drug classes for HIV medications include capsid inhibitors, entry inhibitors, nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), integrase strand transfer inhibitors (ISTIs), and protease inhibitors (PIs) (10).  

Lenacapavir is a capsid inhibitor often prescribed at 600 mg once a day that works to distort HIV capsid protein function, thus reducing the influence of HIV in the body. Similar to HSV medications, dosage, frequency, and co-administration of other HIV-related antivirals will depend on patient response to the medication, patient health history, and patient condition (10).  

Entry inhibitors work to reduce the HIV viral load by blocking HIV from entering CD4 cells. There are three main types of entry inhibitors: CCR5 antagonists, fusion inhibitors, and attachment inhibitors.  

Maraviroc is an entry inhibitor pill often prescribed at 150, 300, or 600 mg, depending on patient health history and severity of HIV. Maraviroc acts as a CCR5 antagonist, where the method of action is blocking HIV from binding to the chemokine coreceptor 5 (CCR5) (10).  

Enfuvirtide is an injection medication and acts as an entry inhibitor by preventing HIV from fusing to CD4 cells walls. Fostemsavir is another entry inhibitor pill often prescribed at 600mg twice daily, where the method of action is binding to the HIV glycoprotein GP120 to inhibit HIV attachment to host T cells (10).  

NRTIs include abacavir, emtricitabine, lamivudine, tenofovir alafenamide, tenofovir disoproxil fumarate, zidovudine, didanosine, and stavudine. NRTIs are often given in pairs, where the most commonly prescribed pairs are tenofovir alafenamide-emtricitabine, tenofovir disoproxil fumarate-emtricitabine, and abacavir-lamivudine. Clinical management of HIV with NRTIs can depend on severity of HIV, co-existing health conditions, and patient health history. NRTIs' method of action involves undergoing intracellular phosphorylation mediated by host enzymes, allowing HIV's DNA chains to be depleted over time (10).  

NNRTIs work to suppress the HIV viral load by preventing HIV-1 reverse transcriptase from creating new nucleotides to the HIV DNA chain. Common NNRTI medications include efavirenz, nevirapine, doravirine, etavirine, and rilpivirine (10).  

INSTIs work to suppress the HIV viral load by targeting the strand transfer step of HIV DNA replication, thus reducing the rate in which the HIV DNA replicates. Common INSTI medications include raltegravir, elvitegravir, dolutegravir, and bictregravir (10). 

Protease inhibitors work to suppress the HIV viral load by suppressing the cleaving of Gag-Pol polyproteins in HIV-infected cells, thus having cells that are not mature enough to be infectious in the body. Protease inhibitors include atazanavir, darunavir, lopinavir, indinavir, fosamprenavir, nelfinavir, saquinavir, and tipranavir (10).  

Oral Antiviral Side Effects 

Every medication has the possibility of side effects, and oral antivirals are no exception.  

• The most common side effects of acyclovir and valacyclovir include fatigue, GI upset, confusion, headache, and neurotoxicity (19). Most common side effects of famciclovir include GI upset, headache, and hepatoxicity (20).  
• Common side effects of lenacapavir include GI upset, changes in blood sugar, changes in urine, and hepatic dysfunction (10).  
• Side effects commonly noted in maraviroc include skin rash, GI upset, sexual dysfunction, and anemia. There is an FDA boxed warning for maraviroc and hepatoxicity (10).  
• The most common side effects of fostemsavir include increased serum creatine, prolonged QT elongation, changes in cholesterol levels, changes in glucose levels, changes in liver, and confusion (10).  

• Common side effects of NRTIs include mitochondrial toxicity, which can have a significant range of clinical presentations, such as hepatic dysfunction, peripheral neuropathy, changes in cholesterol levels, or changes in pancreatic function. Zidovudine, in particular, has an FDA boxed warning for hematological toxicity, myopathy, and severe hepatomegaly (10).  
• Common side effects of NNRTIs include GI upset, headache, skin rash, changes in cholesterol levels, and changes in glucose levels. The most commonly prescribed NNRTIs rilpivirine and etavirine have possible side effects of prolonged QT interval and neuropsychological effects (10).  
• Side effects commonly reported with INSTIs include changes in weight, headache, and GI upset. Dolutegravir and raltegravir in particular have possible side effects of myopathy, elevations in creatine phosphokinase (CPK), and rhabdomyolysis (10).  
• Common side effects of protesase inhibitors include changes in blood glucose, changes in cholesterol levels, hepatotoxicity, PR interval prolongation, GI upset, and headache (10).  

Oral Antiviral Alternatives 

HIV and HSV are complex, chronic conditions that are often managed with antiviral medications and require patient monitoring to observe patient response to the medications and clinical presentation.  

While antiviral medications are considered the standard for evidence-based care for HSV and HIV, lifestyle modifications to strengthen one's immune system, such as increased sleep, decreased stress, and a healthy diet are thought to play a role in HIV and HSV management (10). Condom use can help prevent the transmissions of STIs (1). 

Nursing Considerations 

Nurses remain the most trusted profession for a reason, and APRNs are often pillars of patient care in several health care settings. Patients turn to nurses for guidance, education, and support.  

While there is no specific guideline for the nurses' role in STI education and management, here are some suggestions to provide quality care for patients currently taking oral medications to manage STIs or concerned about possibly having a STI. 

• Take a detailed health history. Often times, sexual health, such as pain during sex or bleeding after sex, are often dismissed in health care settings. If a patient is complaining of symptoms that could be related to a STI, inquire more about that complaint.  

Ask about how long the symptoms have lasted, what treatments have been tried, if these symptoms interfere with their quality of life, and if anything alleviates any of these symptoms. If you feel like a patient's complaint is not being taken seriously by other health care professionals, advocate for that patient to the best of your abilities.  

• Review medication history at every encounter. Often times, in busy clinical settings, reviewing health records can be overwhelming. Millions of people take antibiotics and antiviral medications for various infections. Ask patients how they are feeling on the medication, if their symptoms are improving, and if there are any changes to medication history.  

• Be willing to answer questions about sexual health and oral STI medication options. Society stigmatizes open discussions of prescription medication and sexual health. There are many people who do not know about safe sexual practices, the long-term effects of undiagnosed or repeat STIs, or possible STI treatment options.  

Be willing to be honest with yourself about your comfort level discussing topics and providing education on oral STI medications and STI prevention.  

• Communicate the care plan to other staff involved for continuity of care. For several patients, especially for patients with viral STI infections or re-current STIs, care often involves a team of mental health professionals, nurses, specialists, pharmacies, and more. Ensure that patients' records are up to date for ease in record sharing and continuity of care. 
• Stay up to date on continuing education related to oral STI medications and STIS. This is essential, as evidence-based information is always evolving and changing. You can then present your new learnings and findings to other health care professionals and educate your patients with the latest information.  

You can learn more about the latest research on oral STI medications and STIs by following updates from evidence-based organizations.  

How can nurses identify if someone has a STI?  

Unfortunately, it is not possible to look at someone with the naked eye and determine if they have an STI. While some people might have visible STI symptoms, such as a wart or discharge, the most common STI symptom is no symptom.  

APRNs can identify and diagnose if someone has a STI by taking a complete health history, listening to patient's concerns, and offering STI testing. 

What should patients know about oral STI medication?  

Patients should know that anyone has the possibility of experiencing side effects on antiviral or antibiotic medications for STIs, just like any other medication. Patients should be aware that if they notice any changes in their vision, experience any sharp headaches, or feel like something is a concern, they should seek medical care.  

Because of social stigma associated with sexual health, people are hesitant to seek medical care because of fear, shame, and embarrassment. However, as more research and social movements discuss sexual health more openly, there is more space and awareness for STI prevention and management.  

Nurses should also teach patients to advocate for their own health in order to avoid untreated or undetected STIs and possible unwanted side effects of oral STI medication.  

Here are important tips for patient education in the inpatient or outpatient setting:  

• Tell the health care provider of any existing medical conditions or concerns (need to identify risk factors) 
• Tell the health care provider of any existing lifestyle concerns, such as alcohol use, other drug use, sleeping habits, diet, menstrual cycle changes (need to identify lifestyle factors that can influence SSRI use and major depressive disorder management) 
• Tell the health care provider if you have any changes in your pelvis, such as pain with urination, pain during sex, or bleeding during or after sex (potential STI symptoms) 
• Tell the nurse of health care provider if you experience any pain that increasingly becomes more severe or interferes with your quality of life 

• Keep track of your sexual health, medication use, and health concerns via an app, diary, or journal (self-monitoring for any changes) 
• Tell the health care provider right away if you are having thoughts of hurting yourself or others (possible increased risk of suicidality is a possible side effect for ____ use) 
• Take all prescribed medications as indicated and ask questions about medications and possible other treatment options, such as non-pharmacological options or surgeries 
• Tell the health care provider if you notice any changes while taking medications or on other treatments to manage STIs (potential worsening or improving health situation) 

Research Findings 

There is extensive publicly available literature on antibiotics and antiviral medications via the National Institutes of Health and other evidence-based journals.  

If a patient is interested in participating in clinical trial research, they can seek more information on clinical trials from local universities and health care organizations.

Conclusion 

STIs affect millions of people nationwide and can affect anyone who is having sex. Oral STI medication is often a first-line pharmacological option for managing several STIs. However, clinical presentation and symptom management for STIs can vary widely. Education and awareness of different STIs and different oral STI medications can influence the lives of many people in a healthy way.

Case Study #1 

Sabrina is a 26-year-old Latina woman working as a teacher. She arrives for her annual exam at the local health department next to her place of work. She reports nothing new in her health, but she says she's been having some pain when she has sex and sometimes bleeds after sex.  

Sabrina said she's never felt this way before, and she denies having any major changes in her life that could be affecting her pelvic health. She heard one of her friends talk about STIs, but she doesn't think she has any because she tested negative for STIs a few years ago. She wants to know if she could have an STI and what else could be causing pain and bleeding during sex.

Case Study (Continued) 

Sabrina agrees to provide a urine sample, complete a Pap smear, and complete bloodwork later this week. She said that no health care provider talked to her about sexual health, but she heard about different STI symptoms from her friends recently.  

She's back in the office a few weeks later to discuss her lab results. Her Pap smear shows that she is HPV negative, her bloodwork is unremarkable, and her urine culture is positive for trichomoniasis and chlamydia. Sabrina states that she is shocked about the results since she is in a monogamous relationship with her boyfriend. She would like to know how she contracted two STIs.  

Case Study (Continued) 

Sabrina is willing to take antibiotics for her STI infections. She has questions about how to take these medications since she read online that antibiotics can interfere with the birth control pill. She reports taking a birth control pill called Sprintec. She also wants to know if there is a way to have treatment for her boyfriend as well and if he can get tested for STIs. Sabrina also wants to be pregnant in the future, and she would like to know if these STIs can affect her fertility.  

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