Theophylline


Article Author:
Talha Jilani


Article Editor:
Sandeep Sharma


Editors In Chief:
Timothy Craig
Yoon Kim
Robert Hostoffer


Managing Editors:
Carrie Smith
Abdul Waheed
Frank Smeeks
Kristina Soman-Faulkner
Scott Dulebohn
Sobhan Daneshfar
William Gossman
Pritesh Sheth
John Shell
Matthew Varacallo
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Richard Ciresi
Hajira Basit
Phillip Hynes


Updated:
4/8/2019 8:47:37 AM

Indications

Theophylline is a drug derived from methylxanthine (a purine derivative) and has smooth muscle relaxant, bronchial dilation, diuretic, cardiac and central nervous system (CNS) stimulant activities. Naturally present in tea and cocoa beans in small amounts, it was initially extracted and synthesized in 1895, and used as a diuretic. In 1922, it was introduced for the clinical treatment of asthma, after its bronchodilator effect had been identified. It used in the treatment of various respiratory conditions which obstruct the airways such as asthma and chronic obstructive pulmonary disease (COPD).

Medical Uses

  • Chronic obstructive pulmonary disease
  • Asthma
  • Infant Apnea
  • Anosmia which is currently under investigation. A clinical study in 2008 reported that theophylline could potentially improve the sense of smell in those with anosmia.

Asthma Exacerbations

Treatment of asthma exacerbation with theophylline is not recommended by the current clinical practice guidelines (2018 GINA Report, Global Strategy for Asthma Management and Prevention; National asthma education and prevention program-NAEPP 2007).

COPD Management

According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) in 2018, the management of acute COPD with IV theophylline is not recommended by the current clinical practice guidelines due to its significant side effects. [1][2][3][4]

Mechanism of Action

Theophylline relaxes the smooth muscles located in the bronchial airways and pulmonary blood vessels. It also reduces the airway responsiveness to histamine, adenosine, methacholine, and allergens. It exerts these effects mainly through two distinct mechanisms:

  • It acts as a competitive nonselective phosphodiesterase inhibitor (inhibiting type III and type IV phosphodiesterase), which increases the level of intracellular cAMP, activates protein kinase A, inhibits TNF-alpha and leukotriene synthesis, and also decreases inflammation and innate immunity.
  • It is also a nonselective adenosine receptor antagonist. It acts on A1, A2, and A3 receptors with almost the same affinity and this possibly explains the cardiac effects of theophylline. Adenosine-mediated channels also increase the contraction force of diaphragmatic muscles through enhancing their calcium uptake. [2][3][4]

  Other proposed mechanisms of action of theophylline include:

  • It inhibits nuclear factor-kappaB. This prevents the translocation of the pro-inflammatory transcription factor (nuclear factor-kappaB) to the nucleus, reducing the expression of known inflammatory genes in COPD and asthma). 
  • Increases interleukin-10 secretion; interleukin-10 has broad anti-inflammatory effects.
  • Increases histone deacetylase 2 through inhibiting phosphoinositide 3-kinase-delta.
  • Decreases Poly(ADP-ribose)polymerase-1 (PARP-1).
  • Increases apoptosis of inflammatory cells (T cells, neutrophils)

Administration

Theophylline can be used as an oral agent (rapid or slow-release tablets, solution, syrup, or capsule) or in a more soluble form such as aminophylline (an ethylenediamine salt) that can be used orally or intravenously. Cautiously administer theophylline in a patient who has consumed large amounts of foods or drinks with high caffeine content as this could potentially increase the risk of side effects of theophylline.

Intravenous (IV)

Patients can be administered IV theophylline for acute bronchospasm. Those who are not currently taking theophylline should be given a loading dose of 5 to 7 mg/kg intravenously followed by a maintenance dose of 0.4 to 0.6 mg/kg per hour intravenously to maintain serum levels at 10 to 15 mg/L.

IV aminophylline had frequently been used in the management of acute exacerbations of COPD and asthma but is used much less frequently now as it is far less effective than nebulized beta2-agonists. The currently recommended loading dose is 6 to 7 mg/kg administered intravenously over 20 to 30 minutes. After this, a maintenance dose of 0.5 mg/kg per hour is administered. In patients already taking theophylline, or those who have any factors that decrease its clearance from the body, doses should be halved, and its plasma level checked more frequently. In patients with cardiac decompensation, cor pulmonale, older patients or those on medications that are known to decrease theophylline clearance, the infusion rate of theophylline should not be increased above 17 mg per hour unless the patient remains symptomatic, their steady-state serum concentrations are consistently below 10 mcg/mL, and their serum concentrations can be observed at 24-hour intervals. Administering solutions comprising dextrose concurrently through the same administration route as blood may result in hemolysis or pseudoagglutination, and should be avoided.  

Oral

Theophylline tablets are rapidly absorbed, but plasma concentrations show wide fluctuations and are therefore not currently recommended. Several sustained-release preparations that are absorbed in a relatively constant rate provide steady plasma concentrations of the drug over a 12 to 24-hour period. It should be taken consistently with or without food (as this helps to maintain a more consistent serum drug level).

  • The 12-hour formulation: This could be taken once every 24-hours in patients who are non-smokers (who have appropriate total body clearance of theophylline) and in patients who have low dosage requirements. Only after theophylline has titrated to therapeutic levels in the patient, can the 12-hour formulation be considered. The once-daily dosing should be based on the twice-daily dosing and initiated at the end of the every 12-hour dosing interval. Do not give the once-daily dosing to the patient at night (after the evening meal).
  • The 24-hour formulation: Take each morning around the same time and avoid taking it at night (after the evening meal). In patients whom a higher dose is required (13 mg/kg or greater than or equal to 900 mg, whichever one is less), should take the medication less than 60 minutes before a high-fat meal (as a significant increase in the peak serum level and absorption could occur). Patients should consistently take theophylline either in a fasting state or with food (as this helps to maintain a more consistent serum drug level). The twice-daily dosing could be considered for those who metabolize theophylline quickly (for example, smokers, younger patients, and some nonsmoking adults) and those who still have symptoms at the end of the dosing interval. The first dose should be administered in the morning and the second one around 10 to 12 hours after the first dose (but before eating the evening meal). Administration at night should be avoided.

Other Routes

Administering by inhalation is both irritating and ineffective. Administration of theophylline through intramuscular injections is very painful and should never be given.

Dosing Considerations

  • If aminophylline is being administered, the dose should be increased by 25% (as aminophylline is 79% to 86% theophylline).
  • The ideal body weight should be used to calculate the dose.
  • Aminophylline or immediate-release theophylline should be used for per-oral loading. [5][6][7]

Adverse Effects

Theophylline has a very narrow therapeutic window, and its interaction with various other drugs has led to the limitation of its use. The serum theophylline levels must be monitored directly to avoid toxicity as the adverse effects of theophylline are related to its plasma concentration and have been observed when plasma levels exceed 20 mg/L. Some patients have also experienced adverse effects at low plasma concentrations. The dose is gradually increased until therapeutic plasma concentrations are achieved to reduce side effects.

The most common side effects are nausea and vomiting, headache, increased stomach acid secretion, and gastroesophageal reflux, which could be due to PDE inhibition. CNS symptoms (irritability, lightheadedness, and dizziness) have also been observed in patients. In severe cases, seizures have also occurred. At high serum concentrations, adenosine A1A-receptor antagonism could lead to convulsions and cardiac arrhythmias. [8][9][10]

Contraindications

Contraindications

  • Theophylline is contraindicated if the patient previously developed a hypersensitivity reaction to the drug or any component of its formulation (such as allergy to corn-related products (in injection use only).
  • Other contraindications include hypersensitivity to xanthine derivatives and patients with coronary artery disease (where the cardiac stimulation effect of theophylline might prove harmful).

Precautions

  • Patients with cardiovascular disease: Use cautiously in patients who have cardiac arrhythmias (excluding bradyarrhythmias); at it may exacerbate arrhythmias.
  • Patients with cystic fibrosis: Use cautiously in patients with cystic fibrosis, as increased theophylline clearance may occur in these patients.  
  • Patients with hepatic impairment: Use cautiously in patients with hepatic impairment such as cirrhosis, cholestasis, acute hepatitis because there is an increased risk of severe and potentially fatal complications. This is because clearance decreases by 50% or more in these patients. Frequent monitoring and dose reduction of theophylline are required in these patients.
  • Patients with hyperthyroidism: Use cautiously in patients with hyperthyroidism, as increased theophylline clearance may occur.  
  • Patients with peptic ulcer disease: Use cautiously in patients who have active peptic ulcer disease, as the use of theophylline may exacerbate peptic ulcer.
  • Patients with seizure disorders: Use cautiously in patients who have seizure disorders, as use may exacerbate the seizure disorder.

Special Populations 

  • Elderly patients: Use with extreme caution in elderly patients as these patients are at an increased risk of serious theophylline toxicity.  
  • Pediatric patients: The dose must be selected with caution, and regular monitoring of concentrations should be performed (especially if the child is younger than 1 year of age) as the rate of clearance varies greatly in these patients.

Pregnancy

  • Theophylline is classified as a pregnancy category C drug. It should only be used during pregnancy if the potential benefit to the mother outweighs the potential risk to the fetus. [9][10][11]

Monitoring

Because of the small therapeutic window of theophylline and its many side effects, physicians should monitor the following in the patient:

  • The heart rate of the patient
  • CNS effects (headache, insomnia, irritability)
  • The respiratory rate
  • Patient's arterial or capillary blood gases
  • Patient's electrolyte concentrations, fluid balance, and acid-base balance should be monitored during prolonged IV therapy.

Serum theophylline levels should be checked after the initiation of therapy, prior to increasing dose and if any signs or symptoms of toxicity are observed. Worsening of the current illness, an occurrence of a new illness, or any change in the patient's treatment protocol that may alter theophylline clearance should also prompt the physician to check serum levels of theophylline. Attention should also be paid to the infusion site.

Oral Theophylline

For patients taking oral treatment, serum concentrations are monitored at 6-month intervals for rapidly developing children and at annual intervals for all others patients (if their symptoms are well controlled).

IV Theophylline

Loading dose: The serum concentration of theophylline should be checked 30 minutes after the completion of an intravenous loading dose in patients with no theophylline use in the last 24 hours to determine if additional loading may be required (if the serum concentration is less than 10 mcg/mL) or to delay initiating the constant IV infusion (if the serum concentration is greater than 20 mcg/mL).

Infusion: Serum concentration of theophylline should be measured to one expected half-life (approximately 4 hours in young children [ages 1 to 9 years], or around 8 hours in otherwise healthy adults, who do not smoke) after administering a continuous infusion, then checked every 12 to 24 hours to establish if any further adjustments are required, and then at 24 hour intervals for the remainder of the infusion.

Therapeutic Levels for Theophylline

  • For children: 5 to 15 mcg/mL
  • For adults: 10 to 20 mcg/mL  
  • Toxic serum concentration: greater than 20 mcg/mL. [12][13][14][15][16]

Toxicity

As with other methylxanthines, theophylline toxicity can lead to gastrointestinal distress, insomnia, and tremor. Severe nausea and vomiting, cardiac arrhythmias, hypotension, and convulsions have also been reported, more commonly in cases of overdosage. Very large overdoses, such as those during suicide attempts could potentially be lethal because of the development of arrhythmias and convulsions.

  • Activated charcoal may prevent absorption by adsorbing the drug in the intestine.
  • Beta-blockers could potentially be used for reversing the severe cardiovascular toxicity caused by theophylline. 
  • Intravenous benzodiazepines may abort seizures. [9][10][11]

Enhancing Healthcare Team Outcomes

Theophylline is often prescribed by the nurse practitioner, primary care provider, pulmonologist, internist and the emergency department physician. However, all healthcare workers who prescribe this medication should be familiar with its adverse effect profile. The drug has a low therapeutic index and known to cause many unpleasant side effects, including life-threatening arrhythmias. Drug levels should be obtained regularly and close monitoring of the patient is essential. With the availability of better and safer bronchodilators, the use of theophylline should not be routine.


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Theophylline - Questions

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A patient has been taking theophylline but has grown weaker. The patient states, "I can no longer swallow pills." Which is the best action for you to take?



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A patient has emphysema and is receiving theophylline to treat bronchospasm. The patient's serum theophylline concentration is monitored. What is the therapeutic range?



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A patient with asthma is seen in the emergency room. He has been on a number of asthmatic drugs, including theophylline. Which of the following increases the levels of theophylline?



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A female with a long history of asthma presents to the emergency room with general fatigue and palpitations. She is on theophylline. Which of the following is not a side effect of theophylline?



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When theophylline is prescribed for asthma, which of the following is not a common side effect?



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An asthmatic individual receives a medication and soon develops nausea, tremors, palpitations, and vomiting. Which of the following drugs is most likely responsible for the patient's symptoms?



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Which medication decreases airway resistance in asthmatic patients?



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Theophylline relieves asthma by which of the following mechanisms?



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The methylxanthine, theophylline, acts by inhibiting which of the following?



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Which is true of theophylline?



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In which situation is clearance of theophylline increased?



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Which of the following medications can increase the serum levels of theophylline?



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What is the mechanism of action of theophylline?



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Which of the following agents has undergone declining use in the treatment of asthma?



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In chronic obstructive pulmonary disease, which of the following is not an action of theophylline?



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Which of the following medications would necessitate an increase in theophylline dosing?



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Which of the following significantly decreases the clearance of theophylline?



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Which of the following drug is a methylxanthine?



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A 25-year-old patient whose previous doctor was aged and just retired from practice presents for care. He is asthmatic and on theophylline monotherapy. Which of the following statements is most accurate concerning the way in which his asthma is being managed on arrival to your clinic?



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You have an adult patient who is receiving theophylline for their emphysema. What is the therapeutic level of serum theophylline?



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A 10-year-old girl with treatment-resistant asthma is receiving maintenance therapy with theophylline. Her daily bronchospasms have decreased from twice a day to once a week, and this has been controlled by albuterol. Which of the following may be safely administered with theophylline?



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Theophylline - References

References

Pacifici GM, Clinical pharmacology of theophylline in preterm infants: effects, metabolism and pharmacokinetics. Current pediatric reviews. 2014;     [PubMed]
Essayan DM, Cyclic nucleotide phosphodiesterases. The Journal of allergy and clinical immunology. 2001 Nov;     [PubMed]
Weinberger M,Hendeles L, Theophylline in asthma. The New England journal of medicine. 1996 May 23;     [PubMed]
Wettengel R, [Theophylline--past present and future]. Arzneimittel-Forschung. 1998 May;     [PubMed]
Jonkman JH,van der Boon WJ,Balant LP,Schoenmaker R,Holtkamp A, Chronopharmacokinetics of theophylline after sustained release and intravenous administration to adults. European journal of clinical pharmacology. 1984;     [PubMed]
Freitag A, Aminophylline injection and theophylline tablets: Acute response in partially reversible chronic airway obstruction. The Medical journal of Australia. 1976 Apr 3;     [PubMed]
Cova D,Cuglituri G,Rossini L,Bonfardeci G, Comparative dose study of a theophylline sustained-release tablet formulation after repeated administrations. International journal of clinical pharmacology, therapy, and toxicology. 1989 Jun;     [PubMed]
Lal D,Manocha S,Ray A,Vijayan VK,Kumar R, Comparative study of the efficacy and safety of theophylline and doxofylline in patients with bronchial asthma and chronic obstructive pulmonary disease. Journal of basic and clinical physiology and pharmacology. 2015 Sep;     [PubMed]
Hendeles L,Weinberger M, Avoidance of adverse effects during chronic therapy with theophylline. European journal of respiratory diseases. Supplement. 1980;     [PubMed]
Hansel TT,Tennant RC,Tan AJ,Higgins LA,Neighbour H,Erin EM,Barnes PJ, Theophylline: mechanism of action and use in asthma and chronic obstructive pulmonary disease. Drugs of today (Barcelona, Spain : 1998). 2004 Jan;     [PubMed]
Stavric B, Methylxanthines: toxicity to humans. 1. Theophylline. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 1988 Jun;     [PubMed]
Hopkins ME,MacKenzie-Ross RV, Case Report: The risks associated with chronic theophylline therapy and measures designed to improve monitoring and management. BMC pharmacology     [PubMed]
Sohn JA,Kim HS,Oh J,Cho JY,Yu KS,Lee J,Shin SH,Lee JA,Choi CW,Kim EK,Kim BI,Park EA, Prediction of serum theophylline concentrations and cytochrome P450 1A2 activity by analyzing urinary metabolites in preterm infants. British journal of clinical pharmacology. 2017 Jun;     [PubMed]
Pesce AJ,Rashkin M,Kotagal U, Standards of laboratory practice: theophylline and caffeine monitoring. National Academy of Clinical Biochemistry. Clinical chemistry. 1998 May;     [PubMed]
Mounié J,Richard L,Ribon B,Hersant J,Sarmini H,Houin G, Methods of theophylline assay and therapeutic monitoring of this drug. Annales de biologie clinique. 1990;     [PubMed]
Aronson JK,Hardman M,Reynolds DJ, ABC of monitoring drug therapy. Theophylline. BMJ (Clinical research ed.). 1992 Nov 28;     [PubMed]

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