thrombolytic therapy

Thrombolytic Therapy

Definition

Thrombolytic therapy is the use of drugs that dissolve blood clots.

Purpose

When a blood clot forms in a blood vessel, it may cut off or severely reduce blood flow to parts of the body that are served by that blood vessel. This can cause serious damage to those parts of the body. If the clot forms in an artery that supplies blood to the heart, for example, it can cause a heart attack. A clot that cuts off blood to the brain can cause a stroke. Thrombolytic therapy is used to dissolve blood clots that could cause serious, and possibly life-threatening, damage if they are not removed. Research suggests that when used to treat stroke, thrombolytic therapy can prevent or reverse paralysis and other problems that otherwise might result.Thrombolytic therapy also is used to dissolve blood clots that form in tubes put into people's bodies for medical treatments, such as dialysis or chemotherapy.

Description

Thrombolytic therapy uses drugs called thrombolytic agents, such as alteplase (Activase), anistreplase (Eminase), streptokinase (Streptase, Kabikinase), urokinase (Abbokinase), and tissue plasminogen activator (TPA) to dissolve clots. These drugs are given as injections, only under a physician's supervision.

Recommended dosage

The physician supervising thrombolytic therapy decides on the proper dose for each patient. He or she will take into account the type of drug, the purpose for which it is being used, and in some cases, the patient's weight.

Precautions

For thrombolytic therapy to be effective in treating stroke or heart attack, prompt medical attention is very important. The drugs must be given within a few hours of the beginning of a stroke or heart attack. However, this treatment is not right for every patient who has a heart attack or a stroke. Only a qualified medical professional can decide whether a thrombolytic agent should be used. To increase the chance of survival and reduce the risk of serious, permanent damage, anyone who has signs of a heart attack or stroke should get immediate medical help.Thrombolytic therapy may cause bleeding. Usually this is not serious, but severe bleeding does occur in some people. This is especially likely in older people. To lower the risk of serious bleeding, people who are given this drug should move around as little as possible and should not try to get up on their own unless told to do so by a health care professional. Following all the instructions of the health care providers in charge is very important.Thrombolytic therapy may be more likely to cause serious bleeding in people who have certain medical conditions or have recently had certain medical procedures. Before being given a thrombolytic agent, anyone with any of these problems or conditions should tell the physician in charge about it:

blood disease or current or past bleeding problems in any part of the body
heart or blood vessel disease
stroke (recent or in the past)
high blood pressure
brain tumor or other brain disease
stomach ulcer or colitis
severe liver disease
active tuberculosis

recent falls, injuries, or blows to the body or head
recent injections into a blood vessel
recent surgery, including dental surgery
tubes recently placed in the body for any reason
recent delivery of a baby

In addition, anyone who has had a recent streptococcal (strep) infection should tell the physician in charge. Some thrombolytic agents may not work properly in people who have just had a strep infection, so the physician may want to use a different drug.People who take certain medicines may be at greater risk for severe bleeding when they are given a thrombolytic agent.Women who are pregnant should tell the physician in charge before being given a thrombolytic agent. There is a slight chance that a woman who is given thrombolytic therapy during the first five months of pregnancy will have a miscarriage. However, streptokinase and urokinase have both been used without problems in pregnant women.After being treated with thrombolytic therapy, women who are breastfeeding should check with their physicians before starting to breastfeed again.

Side effects

Anyone who has fever or who notices bleeding or oozing from their gums, from cuts, or from the site where the thrombolytic agent was injected should immediately tell their health care provider.People who are given thrombolytic therapy should also be alert to the signs of bleeding inside the body and should check with a physician immediately if any of the following symptoms occur:

blood in the urine
blood or black, tarry stools
constipation
coughing up blood
vomiting blood or material that looks like coffee grounds
nosebleeds
unexpected or unusually heavy vaginal bleeding
dizziness
sudden, severe, or constant headaches
Pain or swelling in the abdomen or stomach
back pain or backache
severe or constant muscle pain or stiffness
stiff, swollen, or painful joints

Other side effects of thrombolytic agents are possible. Anyone who has unusual symptoms during or after thrombolytic therapy should tell a health care professional.

Interactions

People who take certain medicines may be at greater risk for severe bleeding when they receive a thrombolytic agent. Anyone who is given a thrombolytic agent should tell the physician in charge about all other prescription or nonprescription (over-the-counter) medicines he or she is taking. Among the medicines that may increase the chance of bleeding are:

aspirin and other medicines for pain and inflammation
blood thinners (anticoagulants)
antiseizure medicines, such as Depakote (divalproex) and Depakene (valproic acid)
cephalosporins, such as cefamandole (Mandol), cefoperazone (Cefobid), and Cefotetan (Cefotan)

Key terms

Arteries — Blood vessels that carry blood away from the heart to the cells, tissues, and organs of the body.Blood clot — A hard mass that forms when blood gels.Chemotherapy — Treatment of an illness with chemical agents. The term is usually used to describe the treatment of cancer with drugs.Dialysis — A process used in people whose kidneys are not working well. By way of a filtering machine, dialysis separates waste and other useless materials from the blood—a job the kidneys usually do.Paralysis — Loss of the ability to move one or more parts of the body.Stroke — A serious medical event in which blood flow to the brain is stopped. This may be because of a blood clot in an artery or because an artery has burst. Strokes may cause paralysis and changes in speech, memory, and behavior.Also, anyone who has been treated with anistreplase or streptokinase within the past year should tell the physician in charge. These drugs may not work properly if they are given again, so the physician may want to use a different thrombolytic agent.

therapy

[ther´ah-pe] treatment.activity therapy in the nursing interventions classification, a intervention" >nursing intervention defined as the prescription of and assistance with specific physical, cognitive, social, and spiritual activities to increase the range, frequency, or duration of an individual's (or group's) activity.aerosol therapy see aerosol therapy.animal-assisted therapy in the nursing interventions classification, a intervention" >nursing intervention defined as the purposeful use of animals to provide affection, attention, diversion, and relaxation.anticoagulant therapy see anticoagulant therapy" >anticoagulant therapy.antineoplastic therapy see antineoplastic therapy.antiplatelet therapy the use of inhibitors" >platelet inhibitors such as aspirin, dipyridamole, or sulfinpyrazone, to inhibit platelet adhesion or aggregation and so prevent thrombosis, alter the course of atherosclerosis, or prolong vascular graft patency.art therapy in the nursing interventions classification, a intervention" >nursing intervention defined as facilitation of communication through drawings or other art forms.aversion therapy (aversive therapy) a form of behavior therapy" >behavior therapy that uses aversive conditioning, pairing undesirable behavior or symptoms with unpleasant stimulation in order to reduce or eliminate the behavior of symptoms. The term is sometimes used synonymously with conditioning" >aversive conditioning.behavior therapy see behavior therapy.carbon dioxide–oxygen therapy see carbon dioxide–oxygen therapy.chest physical therapy see under physical therapy.client-centered therapy a form of psychotherapy in which the emphasis is on the patient's self-discovery, interpretation, conflict resolution, and reorganization of values and life approach, which are enabled by the warm, nondirective, unconditionally accepting support of the therapist, who reflects and clarifies the patient's discoveries.cognitive therapy (cognitive-behavioral therapy) a directive form of psychotherapy based on the theory that emotional problems result from distorted attitudes and ways of thinking that can be corrected. Using techniques drawn in part from behavior therapy, the therapist actively seeks to guide the patient in altering or revising negative or erroneous perceptions and attitudes.collapse therapy a formerly common treatment for pulmonary tuberculosis in which the diseased lung was collapsed in order to immobilize it and allow it to rest. pneumonolysis and thoracoplasty are methods still sometimes used to collapse a lung and allow access during thoracic surgery.combined modality therapy treatment of cancer using two or more types of therapy, such as with chemoradiotherapy. Called also multimodality therapy.compression therapy treatment of insufficiency" >venous insufficiency, varicose veins" >varicose veins, or venous ulceration of the lower limbs by having the patient wear compressing garments such as support hose.continuous renal replacement therapy hemodialysis or hemofiltration done 24 hours a day for an extended period, usually in a critically ill patient.convulsive therapy treatment of mental disorders, primarily depression, by induction of convulsions" >convulsions. The type almost universally used now is electroconvulsive therapy" >electroconvulsive therapy (ECT), in which the convulsions are induced by electric current. In the past, drugs were sometimes used.couples therapy marital t.diet therapy treatment of disease by regulation of the diet" >diet.electroconvulsive therapy (ECT) (electroshock therapy) see electroconvulsive therapy.endocrine therapy treatment of disease by means of hormones; called also hormonal or hormone therapy.estrogen replacement therapy administration of an estrogen to treat estrogen deficiency, such as that occurring after menopause; there are a number of indications, including the prevention of postmenopausal osteoporosis and coronary artery disease, and the prevention and treatment of vasomotor symptoms such as hot flashes and of thinning of the skin and vaginal epithelium, atrophic vaginitis, and vulvar atrophy. In women with a uterus, a progestational agent is usually included to prevent endometrial hyperplasia. Called also hormone replacement therapy.exercise therapy: ambulation in the nursing interventions classification, a intervention" >nursing intervention defined as promotion of and assistance with walking to maintain or restore autonomic and voluntary body functions during treatment and recovery from illness or injury.exercise therapy: balance in the nursing interventions classification, a intervention" >nursing intervention defined as use of specific activities, postures, and movements to maintain, enhance, or restore balance.exercise therapy: joint mobility in the nursing interventions classification, a intervention" >nursing intervention defined as the use of active or passive body movement to maintain or restore joint flexibility.exercise therapy: muscle control in the nursing interventions classification, a intervention" >nursing intervention defined as the use of specific activity or exercise protocols to enhance or restore controlled body movement.family therapy 1. group therapy of the members of a family, exploring and improving family relationships and processes, understanding and modifying home influences that contribute to mental disorder in one or more family members, and improving communication and collective, constructive methods of problem-solving.2. in the nursing interventions classification, a intervention" >nursing intervention defined as assisting family members to move their family toward a more productive way of living.gold therapy chrysotherapy.group therapy see group therapy.helium-oxygen therapy see helium-oxygen therapy" >helium-oxygen therapy.hemodialysis therapy in the nursing interventions classification, a intervention" >nursing intervention defined as management of extracorporeal passage of the patient's blood through a hemodialyzer. See also hemodialysis.hemofiltration therapy in the nursing interventions classification, a intervention" >nursing intervention defined as cleansing of acutely ill patient's blood via a hemofilter controlled by the patient's hydrostatic pressure. See also hemofiltration.highly active antiretroviral therapy (HAART) the aggressive use of extremely potent antiretroviral agents in the treatment of human immunodeficiency virus infection.hormonal therapy (hormone therapy) endocrine therapy.hormone replacement therapy the administration of hormones to correct a deficiency; usually used to denote therapy" >estrogen replacement therapy occurring after menopause.host modulating therapy efforts to control periodontal disease by directly targeting the host response; an example is the use of drugs that do this, such as sub-antimicrobial doses of doxycycline, nonsteroidal antiinflammatory drugs, or bisphosphonates.humidification therapy (humidity therapy) the therapeutic use of air supersaturated with water to prevent or correct a moisture deficit in the respiratory tract; see also humidity therapy.immunosuppressive therapy therapeutic immunosuppression. inhalation therapy the term formerly used for respiratory care (def. 3).intravenous therapy (IV therapy) in the nursing interventions classification, a intervention" >nursing intervention defined as administration and monitoring of intravenous infusions" >intravenous infusions of fluids and medications.leech therapy in the nursing interventions classification, a intervention" >nursing intervention defined as the application of medicinal leeches" >leeches to help drain replanted or transplanted tissue engorged with venous blood.marital therapy a type of family therapy aimed at understanding and treating one or both members of a couple in the context of a distressed relationship, but not necessarily addressing the discordant relationship itself. In the past, the term has also been used in a narrower sense to mean what is defined as marriage therapy, but that is increasingly considered a subset of marital therapy. Called also couples therapy.marriage therapy a subset of marital therapy that focuses specifically on the bond of marriage between two people, enhancing and preserving it.milieu therapy 1. treatment, usually in a psychiatric treatment center, that emphasizes the provision of an environment and activities appropriate to the patient's emotional and interpersonal needs.2. in the nursing interventions classification, a intervention" >nursing intervention defined as the use of people, resources, and events in the patient's immediate environment to promote optimal psychosocial functioning.multimodality therapy combined modality therapy.music therapy 1. the use of music to effect positive changes in the psychological, physical, cognitive, or social functioning of individuals with health or educational problems. Music therapy is used for a wide variety of conditions, including mental disorders, developmental and learning disabilities, Alzheimer's disease and other conditions related to aging, brain injury, substance abuse, and physical disability. It is also used for the management of acute and chronic pain and for the reduction of stress.2. in the nursing interventions classification, a intervention" >nursing intervention defined as using music to help achieve a specific change in behavior or feeling.neoadjuvant therapy in single-agent therapy or combined modality therapy for cancer, initial use of one modality, such as chemotherapy or radiotherapy, to decrease tumor burden prior to use of another modality, usually surgery.nutrition therapy in the nursing interventions classification, a intervention" >nursing intervention defined as administration of food and fluids to support metabolic processes of a patient who is malnourished or at high risk for becoming malnourished. See also nutrition.occupational therapy see occupational therapy.optometric vision therapy a treatment plan prescribed to correct or improve specific dysfunctions of the vision system; it includes, but is not limited to, the treatment of strabismus (turned eye), other dysfunctions of binocularity (eye teaming), amblyopia (lazy eye), accommodation (eye focusing), ocular motor function (general eye movement ability), and visual-motor and visual-perceptual abilities.oral rehydration therapy (ORT) oral administration of a solution of electrolytes and carbohydrates in the treatment of dehydration.oxygen therapy see oxygen therapy.peritoneal dialysis therapy in the nursing interventions classification, a intervention" >nursing intervention defined as administration and monitoring of dialysis solution into and out of the peritoneal cavity. See also peritoneal dialysis.physical therapy see physical therapy.play therapy see play therapy.pulp canal therapy root canal therapy.PUVA therapy [psoralen + ultraviolet A], a form of photochemotherapy for skin disorders such as psoriasis and vitiligo; oral psoralen administration is followed two hours later by exposure to ultraviolet a radiation.radiation therapy see radiation therapy.recreation therapy in the nursing interventions classification, a intervention" >nursing intervention defined as the purposeful use of recreation to promote relaxation and enhancement of social skills.reminiscence therapy in the nursing interventions classification, a intervention" >nursing intervention defined as using the recall of past events, feelings, and thoughts to facilitate pleasure, quality of life, or adaptation to present circumstances.renal replacement therapy therapy such as hemodialysis or transplantation that takes the place of nonfunctioning kidneys. See also therapy" >continuous renal replacement therapy.replacement therapy treatment to replace deficient formation or loss of body products by administration of the natural body products or synthetic substitutes. See also replacement" >replacement. Called also substitution therapy.respiratory therapy respiratory care.root canal therapy that aspect of endodontics dealing with the treatment of diseases of the dental pulp, consisting of partial (pulpotomy) or complete (pulpectomy) extirpation of the diseased pulp, cleaning and sterilization of the empty root canal, enlarging and shaping the canal to receive sealing material, and obturation of the canal with a nonirritating hermetic sealing agent. Called also pulp canal therapy.shock therapy obsolete term for convulsive therapy.simple relaxation therapy in the nursing interventions classification, a intervention" >nursing intervention defined as the use of techniques to encourage and elicit relaxation for the purpose of decreasing undesirable signs and symptoms such as pain, muscle tension, or anxiety.speech therapy the use of special techniques for correction of speech disorders" >speech disorders.substitution therapy replacement therapy.swallowing therapy in the nursing interventions classification, a intervention" >nursing intervention defined as facilitating swallowing" >swallowing and preventing complications of impaired swallowing.thrombolytic therapy the administration of drugs for thrombolysis (dissolution of a thrombus in an artery), to reduce the size of occlusion and thereby reduce damage to muscular tissue; the coronary artery is a commonly used site. Agents commonly used are streptokinase" >streptokinase and tissue plasminogen activator (t-PA).thyroid replacement therapy treatment of hypothyroidism" >hypothyroidism by administration of thyroxine" >thyroxine, usually in the form of levothyroxine" >levothyroxine sodium. Called also thyrotherapy.ultraviolet therapy see ultraviolet therapy.

thrombolytic therapy

intravenous administration of an agent intended to dissolve a clot causing acute ischemia, as in myocardial infarction (MI), stroke, and peripheral arterial or venous thrombosis. Thrombolytic agents degrade fibrin clots by activating plasminogen, a naturally occurring modulator of hemostatic and thrombotic processes. Synthesized by the liver, plasminogen is present in circulating blood and binds to platelets, endothelium, and fibrin. At sites of vascular injury with thrombus formation, tissue plasminogen activator (TPA), produced by endothelial cells, also binds to fibrin and converts fibrin-bound plasminogen to plasmin by cleaving the arginine-valine bond in the 560-561 position of plasminogen. The resulting clot lysis is due to degradation of fibrin threads as well as of glycoproteins required for platelet adhesion and aggregation. Thrombolytic agents in current use mimic the effects of natural TPA. These include alteplase, a TPA produced by recombinant DNA technology; reteplase, a variant of the TPA molecule, also genetically engineered; urokinase, a tissue protein derived from human kidney cell cultures; streptokinase, a product of β-hemolytic streptococci that catalyzes the conversion of plasminogen to plasmin; and anistreplase, an inactive form of plasminogen that is bound to streptokinase and undergoes deacylation after administration, resulting in persistent activation of plasminogen. The latter two products are potentially antigenic and can cause systemic hypersensitivity reactions.
See also: tissue plasminogen activator.

Thrombolytic therapy reduces the in-hospital and 1-year mortality of acute MI by 20-40% when administered promptly (within the first 100 minutes). Some benefit may accrue even after a delay of 6-12 hours. About half those treated for acute MI with a thrombolytic agent have patent coronary arteries after 90 minutes. However, 30% experience reinfarction at the same site within 3 months. Emergency percutaneous transluminal coronary angioplasty (PTCA) may provide better survival figures, but can only be undertaken in a setting where emergency coronary artery bypass graft (CABG) is feasible in case of failure. Streptokinase has sometimes been preferred to TPA in acute MI because it is much less expensive. However, an exhaustive analysis has shown that the use of TPA is cost effective, particularly in anterior MI. That thrombolytic drugs activate platelets partially negates their effectiveness. Combining heparin and the platelet inhibitor abciximab with TPA enhances its ability to restore arterial patency in acute MI. In ischemic stroke, administration of TPA within the first 3 hours has been shown to improve overall outcome at 90 days. The usefulness of thrombolytic therapy in stroke is limited by the difficulty of excluding hemorrhagic stroke and the risk of hemorrhage as a side-effect of therapy. Only TPA is currently recommended in the treatment of stroke. In addition to stroke and MI, thrombolytic therapy has been used in pulmonary embolism, deep venous thrombosis, and peripheral arterial occlusion. Thrombolytic therapy in acute occlusion of a lower-limb artery (or ABG) can obviate the need for surgery in many patients without increasing mortality or amputation rate. Recanalization occurs in as many as 80% of patients. The chief risk of thrombolytic therapy is major hemorrhage. It is contraindicated in the presence of active or recent hemorrhage, active diabetic hemorrhagic retinopathy, recent surgery, intracranial neoplasm or recent head trauma, history of prior hemorrhagic stroke, aortic dissection, acute pericarditis, prolonged or traumatic CPR, pregnancy, or sensitivity to the specific agent.

thrombolytic therapy

Cardiology Any therapy, especially, enzymatic, that dissolves intravascular blood clots and/or fibrin thrombi, digests fibrinogen and other proteins, and recanalizes occluded vessels–usually arteries, to improve circulation; in acute MI, TT is most effective if given at time of Sx onset, if the Pt is stabilized and diagnosis of Q-wave MI is strongly suspected Agents Urokinase, streptokinase, acylated plasminogen streptokinase complex–APSAC, pro-urokinase, tPA Indications PTE, DVT, AMI, peripheral artery disease with intraarterial thrombi

throm·bo·lyt·ic ther·a·py

(throm'bō-lit'ik thār'ă-pē) Intravenous administration of an agent intended to dissolve a clot causing acute ischemia, as in myocardial infarction, stroke, and peripheral arterial or venous thrombosis. Thrombolytic agents degrade fibrin clots by activating plasminogen, a naturally occurring modulator of hemostatic and thrombotic processes. Synthesized by the liver, plasminogen is present in circulating blood and binds to platelets, endothelium, and fibrin. At sites of vascular injury with thrombus formation, tissue plasminogen activator (TPA), produced by endothelial cells, also binds to fibrin and converts fibrin-bound plasminogen to plasmin by cleaving the arginine-valine bond in the 560-561 position of plasminogen. The resulting clot lysis is due to degradation of fibrin threads as well as of glycoproteins required for platelet adhesion and aggregation. Thrombolytic agents in current use mimic the effects of natural TPA. These include alteplase, a TPA produced by recombinant DNA technology; reteplase, a variant of the TPA molecule, also genetically engineered; urokinase, a tissue protein derived from human kidney cell cultures; streptokinase, a product of β-hemolytic streptococci that catalyzes the conversion of plasminogen to plasmin; and anistreplase, an inactive form of plasminogen that is bound to streptokinase and undergoes deacylation after administration, resulting in persistent activation of plasminogen. The latter two products are potentially antigenic and can cause systemic hypersensitivity reactions.
See also: tissue plasminogen activator

thrombolytic therapy

thrombolytic therapy

Thrombolytic Therapy

Definition

Purpose

Description

Recommended dosage

Precautions

Side effects

Interactions

Key terms

therapy

thrombolytic therapy

thrombolytic therapy

throm·bo·lyt·ic ther·a·py

thrombolytic therapy

Words related to thrombolytic therapy

noun therapy consisting of the administration of a pharmacological agent to cause thrombolysis of an abnormal blood clot

Related Words