Introduction

Although tetanus vaccines are now a routine part of a child’s medical care in the UK, tetanus is still a serious disease capable of causing life-threatening symptoms. While vaccination efforts have curbed its incidence in more developed countries, lower income countries still report substantial cases of tetanus every year. Given the severity of the disease, most cases of tetanus involve several weeks in the intensive care unit and various types of medication to manage the symptoms of the disease.

The tetanus disease course is long-lasting and involves serious symptoms. Therefore, treating tetanus effectively requires a multi-pronged approach: stopping production of the bacterial toxin, neutralising unbound toxins, controlling muscle spasms, managing and maintaining the airway, and other supporting treatments. These are all essential in managing the symptoms and progression of the tetanus bacterial infection. Here, we will discuss the strategies and medications associated with each of these treatment stages.

Tetanus

Tetanus is caused by a bacterial infection by the Clostridium tetani species characterised by severe muscle spasms. C. tetani is naturally found in soil and can enter the body through wounds and injuries to the skin. Upon infection, the bacteria produce a toxin that affects the human nervous system and causes the various symptoms of tetanus.

The production of the tetanus vaccine has dramatically decreased the incidence of tetanus in the western world, but developing countries still have a considerable number of tetanus cases every year. This is mostly due to the inadequate cleaning of wounds or injuries as well as the lower levels of tetanus vaccination in these regions.

Symptoms of tetanus

The classic initial presentation of tetanus is the “locked jaw”. This describes the inability of patients to open their mouths due to strong, and often painful, spasms of their masseter (jaw) muscles. Muscle spasms and rigidity subsequently spread to other parts of the body, including the limbs and the chest. This is due to the bacteria toxin reaching the motor neurons and spinal cord of the patient. Clinically, this manifests as:¹

• Muscle stiffness and rigidity
•  Muscle spasms
•  Abnormal, stiff posture and body movements
•  Inability to swallow

Tetanus can cause major complications that can sometimes lead to death. This includes muscle death, breathing issues, and pneumonia. Therefore, it is vital to start treatment immediately.

Tetanus treatment overview

Both urgent and long-term treatment and support is required for patients with a tetanus infection. This normally requires patients to stay in a hospital’s intensive care unit for a few weeks so that they can be monitored and treated fully. 

The severity and duration of tetanus symptoms can vary between individuals. The patient’s medical history and the amount of bacterial toxin in their central nervous system are the two main determinants of the severity of infection. On average, the disease progresses for approximately 14 days, and full recovery may take up to a month.²

The major goals of tetanus treatment are:

1. Stopping the production of the bacterial toxin
2. Neutralising the unbound toxin
3. Controlling and limiting the muscle spasms
4. Airway management
5. Other supporting treatments

We will now explain the importance and role of each of these treatment arms. Common medications or strategies utilised in each will also be described.

Stopping toxin production (antibiotics)

Tetanus disease symptoms are caused by the Clostridium tetani toxin reaching and affecting the central nervous system of an individual. Therefore, it is crucial to kill all Clostridium tetani bacteria in the patient to stop both the production of further bacterial toxins and the progression of the disease.

Firstly, the site of the wound is thoroughly cleaned and debrided. Antibiotics are then administered to clear the bacterial infection. While penicillin G was previously most prescribed in tetanus treatment, metronidazole antibiotics are now considered the gold standard. Typically, 500 mg of metronidazole will be administered intravenously to the patient every 6-8 hours for about a week.¹

Neutralising toxins (antitoxins)

Unfortunately, once the bacterial toxin is bound to the cells of the patient, it is irreversible and treatment is not effective at removing toxins from the central nervous system. However, treatments can be used to neutralise any unbound bacterial toxins. 

This is achieved by administering antitoxin into the patient, which binds to the tetanus toxin and neutralises its ability to bind to and disrupt the function of the nervous system. The tetanus antitoxin, known as human antitetanus immunoglobulin (HTIg), is now the first-line treatment for tetanus treatment.³ The HTIg antitoxin is normally administered via intramuscular injection, enabling it to rapidly circulate through the body.

A single dose of 500 units is currently recommended, with parts of the dose administered around the site of the infected wound.⁴ Recent research efforts have also explored the additional administration of HTIg through intrathecal injection, where it is introduced directly into the spinal canal.⁵

Additionally, recovery from tetanus infection does not confer immunity for subsequent Clostridium tetani infections. Therefore, it is advised that all tetanus patients receive the full course of tetanus vaccination doses upon diagnosis.²

Controlling muscle spasms

Uncontrollable muscle spasms, the main symptom of tetanus infection, are life-threatening. If not effectively managed, they can lead to generalised exhaustion and complications in breathing and nutrition among patients. Therefore, it is essential that drugs are prescribed to limit muscular spasms in patients. 

Benzodiazepine sedatives (such as diazepam) are most commonly used in tetanus infections. This class of medications function as muscle relaxants, anticonvulsants and sedative drugs, and target many symptoms throughout the tetanus disease course.

Benzodiazepines are also relatively affordable, making them suitable for use in lower-income countries. It is generally recommended that 10-30 mg of benzodiazepines are intravenously administered to patients every few hours.⁶ As they tend to be prescribed across several weeks, the dose must be adjusted according to the patient’s drug tolerance and slowly decreased over time.

While benzodiazepines are the most popular medication for controlling muscle spasms in tetanus patients, other treatments can be considered. Magnesium sulphate has been prescribed for tetanus as an anticonvulsant medication.⁷ Additionally, other neuromuscular blocking agents, such as vecuronium, are administered if benzodiazepine is insufficient in more severe cases of the disease.

Airway management

Spasms can also affect the muscles of the chest, neck and back of the patient with tetanus. As a result, muscles that normally control breathing can become rigid or suffer spasms. Many patients therefore require mechanical ventilation to regulate breathing as they receive other treatments for tetanus in the intensive care unit.

It is important to note that mechanical ventilation puts patients at risk of other health issues such as ulcers, tracheal stenosis, and other hospital-acquired infections.² These risks must be considered in more serious tetanus infections that require sustained periods of mechanical ventilation and hospitalisation.

Other treatments/management

Tetanus infection has wide-ranging effects on the patient’s health. Other treatment strategies are discussed below that manage the health consequences of the tetanus disease course:²

• Tube feeding: tube feeding delivers additional nutrients to the gut of patients with tetanus. This is often required as muscles that allow ingestion of food are often rigid or spasming during infection, making feeding difficult. Additionally, the muscle spasms use up lots of energy that must be replaced
• Heart function support: serious cases of tetanus are detrimental to heart function. Many patients experience cardiovascular complications, including increased blood pressure and heart rate. Anticoagulant medication is essential to lower the risk of heart failure⁸
• Physical therapy: physical therapy ensures that the muscles of individuals with tetanus remain healthy and mobile after infection. Tetanus muscle spasms often leave patients with muscle failure and contractures

Summary

A holistic and thorough treatment regime is essential for tetanus due to the serious nature of the disease symptoms. If left untreated, the characteristic muscle spasms associated with tetanus can be fatal.

Therefore, there are multiple treatment arms and medications prescribed throughout the disease course. Stopping the production of bacterial toxin is achieved through wound cleaning and antibiotics. Neutralising existing bacterial toxins is also important and addressed through antitoxins and immunisation. To manage the severe muscle spasms caused by tetanus, anticonvulsant and sedative medications are administered for up to several weeks. Furthermore, serious cases may require airway management, tube feeding, and heart function support to mitigate the effects of muscle spasms in essential organs around the body.