3. Drug application

Question 1

Application route of choice depends on ___ ?

Answer 1

– drug formulation
– product labelling
– required onset of action
– (place of action)
– routes available

Question 2

Indications for per oral medications

Answer 2

– Usually for long-term medications (owner)
– Drug effect on the GI tract (probiotics, activated charcoal)
– Drugs with systemic effect

Question 3

Forms of per oral medications

Answer 3

– peroral formulated drugs (pills, liquids)
– radiography contrast
– gastrointestinal tract studies
– forced feeding

Question 4

Contraindications for per oral drug application

Answer 4

• head and neck trauma (tissue or bone injury , damaged inner action)
• decreased mental state (inability to swallow properly)
• recent surgery (stomach/bowel: <12-24h; oesophagus: longer)
• known/suspected injury of GI tract (perforation, foreign body/ ileus)
• vomiting/regurgitation, dysphagia (antiemetics, feeding position)
• non-cooperative patient (risk of injury)

Question 5

Technique of per oral application

Answer 5

Question 6

Per oral application. Complications

Answer 6

• aspiration ! (-> pneumonia)
• injury of patient (e.g. soft tissue laceration via forceps used)
• injury of person treating their patient
• inappropriate dosage (vomiting, regurgitation, spitting out the drug)

Question 7

Needles

Answer 7

Size: lenght and diameter
• diameter: Gauge (G) (larger gauge – smaller diameter)
• dogs, cats: 18-25 G

Question 8

Size of choice for needle depends on:

Answer 8

• patient size
• administration route (skin thickness, vein size…)
• injection thickness (thicker suspensions or oily: smaller Gauge)
• injection volume (e.g. sc infusion: smaller gauge)

Question 9

Syringes

Answer 9

– 1-10 (50) ml (sc infusion: often directly from inf. bag)
– accurate dosage
– (i.v.: slower administration)
– special: insulin syringe (and needle): scale: I.U

Question 10

Syringes

Question 11

Syringes

Question 12

Indications subcutaneous application

Answer 12

– injectable drugs labelled for sc. use
– fluids (isotonic crystalloid infusions)
– microchip
– hormone implants

– (slower onset of action – sc. fluids and drugs)

Question 13

Contraindications for SC application

Answer 13

– Drugs NOT labelled for sc. use
• oily injections, tissue irritative injections
• Poor s.c. adsorption – enrofloxacin, buprenorphin

– (if faster onset of action required and other admin. route available)

– (relative CI: bleeding diathesis, dermatitis)

Question 14

SC applications. Technique

Answer 14

Question 15

Subcutaneous infusion

Answer 15

• Treat mild dehydration (e.g. chronic kidney patients)

• ONLY isotonic crystalloids!

• NOT: hypertonic, G containing, mannitol, colloids, blood products, lipid or amino acid infusion (tissue necrosis!!!)

• amount: max. 10(-20) ml/kg per spot
– large dogs: max. 200 ml per spot

• warmed fluids

• Use large bore needle, often directly from infusion bag

Question 16

Subcutaneous injection. Complications

Answer 16

Local reactions
• Hemorrhage / hematoma
• Granuloma (vaccines)
• Abscess (sterile / non-sterile)
• Tissue irritation, necrosis
• injection site sarcoma (even years later!)

Systemic reactions
• allergy (hypersensitivity reactions – urticaria, angioedema,anaphylaxis!)
• i.v. application by mistake

Question 17

Indications for IM application

Answer 17

• injectable drugs labelled for IM use
• oily injections: always IM
• tissue irritative drugs: often labelled to (deep) IM use (imidocarb, melarsomine)

Question 18

Contraindications for IM application

Answer 18

• hemorrhagic diathesis! (thrombocytopenia, -pathia, coagulopathy)
• myositis; muscle stiffness e.g. tetanus

Question 19

Intramuscular injection. Where?

Answer 19

• m. supra-, infraspinatus
• m. triceps brachii
• m. quadriceps femoris
• m. semitendinous/ semimembranous dorsal lumbar epaxial muscles

Drug volume: max. 2-5 ml per patient per muscle (dep. on weight)

Question 20

IM injection. Technique

Answer 20

Question 21

IM injection. Complications

Answer 21

• Local reactions
– Hemorrhage/hematoma
– Abscess (sterile / non-sterile)
– Tissue irritation, necrosis
– Peripheral nerve injury! (hamstring mms → sciatic nerve)

• Systemic reactions
– Allergy (hypersensitivity reactions – anaphylaxis!)
– i.v. application by mistake (e.g. oil embolism)

Question 22

IV application. Veins

Answer 22

Via iv catheter, butterfly needle, single iv injection

Appropriate veins:
– v. cephalica antebrachii
– v. saphena lateralis (dog)
– v. femoralis
– v. jugularis
– v. dorsalis pedis

Question 23

Indications for IV injection

Answer 23

– injections labelled for i.v. use
– fast onset of action required & i.v. route available
– (tissue irritative drugs: often i.v.)

Question 24

Contraindication for IV injection

Answer 24

– oily injections or suspensions NEVER i.v.!!!!!
– (known/suspected hypersensitivity reaction to the drug or product!)

Question 25

IV injection. Technique

Answer 25

• Aseptic technique (Clipping the hair, disinfection of the skin)
• Vein punction in 15-30° angle
• Aspirate blood prior injection
• Release vein compression
• Inject slowly

Question 26

IV injection. Complications

Answer 26

• Local reactions
– hemorrhage, hematoma
– phlebitis, thrombophlebitis, thrombosis
– Paravenous injection and necrosis
propofol, barbiturates; bradycardia, cardiac arrest – potassium, calcium etc.)

• Systemic reactions
– hypersensitivity reactions – anaphylaxis!!!
– septicaemia
– air embolism
– drug side effects are more likely if given too rapidly (e.g. apnea – propofol, barbiturates; bradycardia, cardiac arrest – potassium, calcium etc.)