Parenteral delivery of chemotherapy Flashcards
Parenteral vs oral
despite the convenience of orally given anti-cancer agents, there have been significant limitations
- cost
- bioavailability
- adherence and side effects have been major issues
-interaction with other medications especially in poly pharmacy
what are IM chemo injections
Intra-muscular injections are given through the skin into the muscle layer.
This involves the use of a larger needle with deeper penetration than the subcutaneous injection.
Absorption of the medication is more rapid then the oral form but slower than intravenous administration.
Not commonly used, reserved for antiemetic drugs
Intra-muscular injection is avoided when possible in patients with low platelets (thrombocytopenia), as bleeding within the muscle can be a complication.
SC chemo treatment
Subcutaneous injections involve the use of a short needle such as those used by diabetics for the injection of insulin.
With subcutaneous injection of chemo treatment, the needle goes into the fatty tissue between the skin and muscle but does not enter as far the muscle layer.
Subcutaneous chemo injections are commonly used for of biologic response modifiers and chemotherapy support drugs.
If a patient’s platelet count is low subcutaneous injections are less likely to cause bleeding than intra- muscular injections.
IV chemo treatment
Most common route to deliver chemotherapy
Bioavailability is 100%
Minimizing side effects such as GI irritation and mucositis
Doses can be given as an IV bolus lasting from a few minutes to a few hours.
Continuous infusions can be given over a few days or for weeks at a time.
Portable pumps allow the medication to be given at a slow rate
what are Methods of IV administration
An angiocatheter or centeral line may be placed in a vein in the arm or hand and then removed after the chemo medication is given.
The in-use time of angiocatheters generally ranges from a few minutes to a few days.
PICC (A peripherally inserted central catheter) line can be inserted and used for six weeks to a few months before it is discontinued.
PICC line insertion involves the placement of a long plastic catheter into one of the larger veins of the arm.
Tunneled and non-tunneled catheters are placed through the skin in the middle of the chest.
Tunneled through the subcutaneous tissue and inserted into the superior vena cava vessel at entrance of the right atrium of the heart
Multiple drugs can be co-administered for extensive chemotherapy.
Port-a-cath. A more permanent option involves the placement of a port-a-cath. The port-a-cath is placed under the skin on the chest. The catheter is then inserted into the superior vena cava vessel at entrance of the right atrium of the heart.
what are other methods if chemotherapy
Intrathecal chemotherapy:
Intraperitoneal:
Intravesicular
Intra-arterial:
Intrapleural:
what is Intrathecal chemotherapy?
Intrathecal chemotherapy: is used when drugs need to reach the cerebrospinal fluid (CSF), the fluid that is in the brain and spinal cord (because of BBB).
what is Intraperitoneal chemotherapy?
Intraperitoneal: Some chemotherapy medications can be given directly into the abdominal cavity. It drains into the cavity that surrounds the organs, not into the stomach or any of the other organs.
What is Intravesicular chemotherapy?
Intravesicular: Intravesicular medications are given with the use of a urinary catheter directly into the bladder, often used for early stage bladder cancer
what is Intra-arterial chemotherapy?
Intra-arterial: Intra-arterial drugs are given into the artery that is supplying the blood to the tumor.
what is Intrapleural chemotherapy?
Intrapleural: Chemotherapy can be given into the pleural cavity (the space between the lung and the lining of the lung).
A malignant pleural effusion is an accumulation of cancerous fluid in the pleural space.
The fluid may cause the lung to collapse, making breathing more difficult. Draining the fluid will help, but the fluid will usually come back unless intrapleural chemotherapy is given. This procedure is also known as pleurodesis.
what is Pharmaceutical considerations for formulation of chemotherapy
Same pharmaceutical requirements for parenteral drug delivery
Solubility –> use emulsions or cosolvents
Avoid suspensions in IV
Sterile pyrogen free
Lower viscosity to avoid irritation
pH adjustments and buffers
Osmolarity should be adjusted
what is osmolarity?
“the concentration of a solution expressed as the total number of solute particles per L”
An equivalent is the number of moles of an ion in a solution, multiplied by the valence of that ion.
If 1 mol of NaCl and 1 mol of CaCl2 dissolve in water, there is 1 Eq Na, 2 Eq Ca, and 3 Eq Cl in that solution.
(The valence of calcium is 2, so for that ion you have 1 mole and 2 equivalents.)
what is EXTRAVASATION?
Extravasation is a complication of intravenous injection therapy. It manifests as tissue damage or irritation caused by inadvertent placement or leakage into the area around the injected vein. Hence extravasation should be suspected if the patient reports pain/swelling.
Drugs can be classified as vesicant (directly cause damage to the vasculature, e.g. doxorubicin, epirubicin, vinca alkaloids) or non-vesicant, which are further classified as irritant or non-irritant.
Vesicants can cause extensive necrosis. Irritants can cause pain at the injection site and along the vein, with or without inflammation.
what is Extravasation injury?
The unintentional instillation or leakage of a drug or substance out of a blood vessel into surrounding tissue.
The damage can affect nerves, tendons, and joints and can continue for months after the initial insult.
The degree of injury ranges from mild skin reaction to severe necrosis. Other possible consequences include: infection; complex regional pain syndrome; and loss of function
In severe cases extravasation injury may lead to amputation
