Theo-24 Sr (Theophylline) – Patient Information
Theo-24 Sr is a brand of theophylline, a medicine used to help improve breathing in certain long-term lung conditions. This medicine is presented as slow-release (Sr) capsules/tablets designed to release the drug steadily over time.
This page is written for patients in the United Kingdom. It explains what Theo-24 Sr is, how it works, how it is usually taken, important interactions and safety points, and what to expect in everyday use.
Quick overview
- Active ingredient: Theophylline
- Form: Slow-release (Sr)
- Used for: Long-term control of breathlessness/wheeze in certain chronic lung diseases (commonly asthma or COPD depending on your clinician’s assessment)
- Why “Sr” matters: The medicine is released gradually, aiming to maintain consistent levels in the body
- Important note: Theophylline has a relatively narrow safety range. Blood level monitoring is often used in practice, especially when starting treatment or if other medicines are added/changed
Basic product information
Theo-24 Sr contains theophylline in a slow-release formulation. This helps reduce peaks and troughs compared with immediate-release forms, but careful dosing and monitoring may still be needed.
Typical strengths: Strengths vary by product availability (for example, 100 mg, 200 mg, 300 mg are commonly seen for slow-release theophylline products). Always check the strength stated on your pack.
How it is taken: Swallow the capsule/tablet whole. Do not crush or chew unless your product instructions specifically say you may (many slow-release formulations must be swallowed whole).
How Theo-24 Sr works (mechanism of action)
Theophylline is a methylxanthine that helps open and relax airways and reduce certain inflammatory effects. It works through multiple actions, including:
- Airway relaxation: It can relax smooth muscle in the airways, helping reduce bronchospasm.
- Improved airflow: It may help improve breathing and reduce wheeze.
- Effects on signalling in cells: It influences pathways involving cyclic nucleotides and other cellular processes.
- Reduced reactivity: It may reduce airway responsiveness to triggers.
Because Theo-24 Sr is a slow-release medicine, it is generally used to provide ongoing control rather than immediate relief of sudden attacks.
Pharmacokinetics (how the body handles the medicine)
Understanding pharmacokinetics can help explain why timing and interactions matter with theophylline.
Absorption
- Slow-release formulations are designed to release the drug steadily after swallowing.
- Absorption can be variable between individuals.
- Changes in metabolism and drug interactions can significantly alter levels.
Distribution
- Theophylline distributes into body tissues and is carried in the bloodstream.
- It can interact with other drugs because of effects on liver enzymes.
Metabolism (breakdown)
- Theophylline is mainly metabolised by the liver (through pathways involving cytochrome P450 enzymes).
- Many medicines and lifestyle factors can increase or decrease the breakdown rate.
- Smoking can increase clearance (often lowering levels), while stopping smoking may raise levels.
Excretion
- Metabolites are eliminated primarily via the kidneys.
- Kidney and liver function can influence theophylline levels, making dose adjustment sometimes necessary.
Why monitoring may be needed
Theophylline has a narrow therapeutic range. This means that the difference between a helpful dose and a potentially harmful dose can be small. Your healthcare team may measure theophylline blood levels (a “serum level”) to help keep treatment safe and effective—especially if you:
- are starting Theo-24 Sr
- are elderly or have liver disease
- have heart failure or significant illness
- start, stop, or change doses of interacting medicines
- change smoking habits
Typical use in the UK
In the UK, Theo-24 Sr (theophylline slow-release) may be used as an add-on treatment for long-term management of conditions such as:
- Asthma (long-term control in selected patients)
- COPD (chronic obstructive pulmonary disease) where appropriate
It is important to note that many modern guidelines emphasise inhaled treatments (such as inhaled corticosteroids and long-acting bronchodilators) for long-term control. Theophylline may still have a role for certain patients who need additional support or who cannot tolerate other options.
Not for sudden attacks: Theo-24 Sr is not intended to relieve immediate breathlessness during an asthma/COPD flare. You should use your rescue inhaler or other fast-acting treatment if prescribed for emergencies.
Indications (when Theo-24 Sr is considered)
Therapy is typically considered for long-term symptom control when your clinician decides the benefits outweigh the risks. Indications can vary depending on individual circumstances and local prescribing practices.
- Asthma: Long-term symptom control in selected patients.
- COPD: Long-term control of symptoms such as breathlessness, particularly when other therapies are insufficient.
Always follow the plan provided by your healthcare professional.
How to take Theo-24 Sr (timing and dosing)
Correct timing and dose planning are essential with slow-release theophylline.
General dosing principles
- Doses depend on age, weight, smoking status, liver function, other medicines, and sometimes blood theophylline levels.
- Your prescriber may start with a lower dose and adjust gradually.
- Because levels can build up, changes in dose or interacting medicines should be managed carefully.
How often it’s taken
Many patients take Theo-24 Sr , but some regimens may vary based on the exact product and clinical plan. Follow your pack instructions and your healthcare professional’s advice.
Timing tips
- Choose a time of day that fits your routine and take it at about the same time each day.
- If you’re adjusting treatment, your clinician may recommend checking blood levels after reaching a steady state.
- If you miss a dose, don’t double up unless your clinician or the product leaflet tells you to. Ask your pharmacist for advice.
How to swallow
- Swallow the capsule/tablet whole with water.
- Do not crush or chew if it is a slow-release formulation.
- Stay upright until swallowed to reduce irritation risk.
Typical starting and maintenance dosing (general information)
Dosing varies widely and should be individualised. Below is a general overview only; it is not a substitute for personal medical advice.
| Patient factor | Why it matters for dosing | Common clinical approach |
|---|---|---|
| Age | Metabolism may be slower | Lower starting dose and slower adjustments |
| Smoking status | Smoking can increase clearance | Dose adjustments if you start/stop smoking |
| Liver function | Reduced clearance can raise levels | Lower doses; close monitoring |
| Other medicines | Drug interactions can raise/lower levels | Review medicines; consider level monitoring |
| Severity of symptoms | Treatment goals differ | Titrate to benefit and tolerability |
If you’d like, tell us your age and which other medicines you take (including inhalers and antibiotics), and we can help you identify likely interaction categories to discuss with your pharmacist.
Food interactions: what to know
Food can affect theophylline absorption for some people. To keep results consistent:
- Try to take Theo-24 Sr in a consistent way each day (e.g., always with or always without food), unless your clinician advises otherwise.
- Large changes in diet can occasionally affect how theophylline behaves.
- If you notice symptoms of under-treatment (persistent breathlessness/wheeze) or side effects (nausea, tremor, palpitations), contact your healthcare team—especially if your meal pattern has changed.
Grapefruit / grapefruit juice: Some medicines can be affected by grapefruit through liver enzyme changes. While not all theophylline interactions are identical, it’s generally wise to avoid large amounts of grapefruit products and check with your pharmacist if you use them regularly.
Alcohol interactions
Alcohol and theophylline may not always interact directly, but alcohol can worsen side effects such as:
- nausea and stomach upset
- sleep disturbance or jitteriness
- palpitations and dizziness
To reduce risk, it’s usually recommended to limit alcohol and avoid binge drinking. If you are taking other medicines for anxiety, sleep, pain, or infections, ask your pharmacist about alcohol safety.
Medicine interactions (important with theophylline)
Interactions are a key concern with theophylline. Some medicines can increase theophylline levels (raising toxicity risk), while others can decrease levels (reducing benefit).
Medicines that may increase theophylline levels
- Some antibiotics (for example, macrolides such as clarithromycin or erythromycin; fluoroquinolones may also be involved)
- Cimetidine (for stomach acid; newer practice may favour alternatives)
- Some antidepressants (certain agents can affect metabolism)
- Other drugs affecting liver enzymes
Medicines that may decrease theophylline levels
- Rifampicin (tuberculosis treatment)
- Carbamazepine and phenytoin (antiepileptics)
- Some inhaled/other medicines may affect overall risk indirectly through clearance or dosing practices
Smoking changes
- Smoking can lower theophylline levels by increasing clearance.
- Stopping smoking can raise levels, increasing risk of side effects.
- If your smoking status changes, discuss this with your prescriber/pharmacist promptly.
Severe interaction warning
If you start a new medicine (especially antibiotics or heart medicines) while on Theo-24 Sr, contact your pharmacist to check whether it could affect theophylline levels. This is one of the most important safety steps you can take.
Safety profile: side effects and what to watch for
Like all medicines, Theo-24 Sr can cause side effects. Many people tolerate it, but because theophylline has a narrow safety range, side effects can indicate that levels are too high.
Common side effects
- Nausea or stomach upset
- Headache
- Trouble sleeping
- Feeling jittery or restless
Serious side effects (seek urgent help if they occur)
Contact urgent medical services or seek urgent advice if you develop symptoms suggestive of significant toxicity, such as:
- Persistent vomiting
- Severe tremor or agitation
- Faster-than-usual or irregular heartbeat
- Chest pain, fainting, or severe dizziness
- Seizures
If you think you may have taken too much, seek urgent medical help immediately.
Who may be at higher risk
- Older adults
- People with liver impairment
- People with certain heart conditions
- Those with fever or significant acute illness
- Those taking interacting medicines
Practical tips for using Theo-24 Sr
- Keep the routine: Take it at the same time each day.
- Don’t change smoking habits without telling your clinician: Theophylline levels can change quickly.
- Review new medicines: When you are prescribed antibiotics or other new drugs, ask your pharmacist to check interactions.
- Track side effects: If you feel unusually shaky, nauseated, or have palpitations, contact your healthcare team.
- Use your inhalers as directed: Theo-24 Sr is not usually a substitute for inhaled rescue or controller therapy.
- Hydration and diet consistency: Avoid major day-to-day changes in diet timing or pattern.
- Use a medication list: Keep an up-to-date list of all medicines and share it at appointments.
Alternative options in the UK
Depending on whether you are being treated for asthma or COPD, alternative therapies may include:
Asthma (long-term control options)
- Inhaled corticosteroids (ICS)
- Long-acting beta2-agonists (LABA) in combination products
- Leukotriene receptor antagonists (some patients may be prescribed alternatives)
- Other add-on therapies as needed for specialist care
COPD (long-term control options)
- Long-acting bronchodilators (LABA, LAMA)
- Combination inhalers (LABA/LAMA and sometimes with inhaled corticosteroid for selected patients)
- Smoking cessation support and pulmonary rehabilitation
Your clinician will decide the best options based on symptoms, lung function, past exacerbations, and medication suitability. Do not stop Theo-24 Sr without discussion—if you’re switching treatments, it should be done safely and gradually where appropriate.
Market and legal context in the United Kingdom
Medicines containing theophylline are regulated in the UK. Theo-24 Sr is supplied according to UK healthcare frameworks and pharmacy regulations. Availability can vary by strength and formulation, and supply may be affected by manufacturing schedules, distribution, and demand.
In the UK, theophylline use is generally approached with caution due to interaction potential and the need for safe dosing. Clinicians often consider blood level monitoring where appropriate, and they review interacting medicines carefully.
Recent guidance and clinical considerations
In the UK, respiratory disease management is guided by evidence-based standards and updates from professional bodies. While specific recommendations for theophylline may differ across patient groups and local practices, common themes include:
- Prioritising inhaled therapies for asthma and COPD control
- Individualised add-on therapy when symptoms persist
- Careful safety monitoring for medicines with narrow therapeutic windows
- Structured review of symptoms, adherence, inhaler technique, and side effects
If you have been prescribed Theo-24 Sr, your clinician may have chosen it after considering your current inhaler regimen, symptom pattern, past response, and interaction risks.
Delivery and availability (UK)
Online pharmacies in the UK may offer delivery options depending on the product’s supply status and regulatory handling requirements.
Availability: Theo-24 Sr strength and pack availability can vary. If an item is temporarily unavailable, some online pharmacies may offer alternatives of the same active ingredient (e.g., different theophylline slow-release brands) depending on stock and clinical suitability.
Delivery: Delivery times vary by supplier and location within the UK (England, Scotland, Wales, Northern Ireland). Many online pharmacies provide standard and express delivery options. Please check the delivery estimate at checkout.
Temperature/storage: Store according to the instructions on the pack, generally in a cool, dry place, away from moisture and heat. Keep out of sight and reach of children.
FAQ
1) What is Theo-24 Sr used for?
Theo-24 Sr is used for long-term control of breathing symptoms in certain chronic lung conditions (such as asthma or COPD) when your healthcare professional decides it is appropriate as part of your treatment plan.
2) Will Theo-24 Sr help immediately during an asthma/COPD flare?
No. Theo-24 Sr is a slow-release medicine intended for ongoing control. If you have sudden symptoms, use your prescribed fast-acting reliever (such as a rescue inhaler) and seek urgent advice if symptoms worsen.
3) Why do I sometimes need blood tests for theophylline?
Theophylline levels can be affected by interactions, smoking, illness, and changes in liver function. Measuring levels helps keep you within a safer range and can guide dose adjustments.
4) Can I drink alcohol while taking it?
Moderation is advised. Alcohol may worsen side effects like nausea, dizziness, and sleep disturbance. Avoid heavy drinking, and ask a pharmacist if you are unsure—especially if you take other medicines.
5) Can I take it with food?
Some patients find that food timing can affect tolerance and consistency. Try to keep how you take it (with or without food) consistent unless your clinician advises otherwise.
6) What should I do if I miss a dose?
Check the specific instructions on your medicine packaging or ask your pharmacist. In general, do not double the dose to make up for a missed one unless told to do so.
7) Are there foods or drinks I should avoid?
Large, sudden dietary changes may affect how you respond. Grapefruit products can interact with certain medicines in general; discuss regular grapefruit use with your pharmacist to be safe.
8) Which medicines commonly interact with theophylline?
Some antibiotics, stomach-acid medicines, certain antidepressants, and anti-epileptic drugs may interact. Because theophylline has a narrow safety range, it’s important to check any new medicine with your pharmacist.
9) What side effects mean the dose may be too high?
Signs can include significant nausea/vomiting, tremor, agitation, persistent palpitations, chest discomfort, severe dizziness, fainting, or seizures. Seek urgent medical help if severe symptoms occur.
10) Can I stop Theo-24 Sr suddenly?
Do not stop without medical advice. If you want to change treatment, your clinician can guide a safe plan based on your symptoms and risk.
Important: This information is designed to help you understand Theo-24 Sr. It does not replace advice from a healthcare professional. If you have questions about your dosing schedule, interactions, or side effects, speak to a pharmacist.
